CSS 高级常用知识
来源：互联网 发布：mac 切换 只有windows 编辑：程序博客网 时间：2024/06/06 12:33
一、Css2 高阶知识（常用）
1. css 优先权
优先权（从低到高）
浏览器缺省设置外部样式表内部样式表（位于 <head> 标签内部）内联样式（在 HTML 元素内部）因此，内联样式（在 HTML 元素内部）拥有最高的优先权，这意味着它将优先于以下的样式声明： 标签中的样式声明，外部样式表中的样式声明，或者浏览器中的样式声明（缺省值）。
2. 背景定位（background-position）
可以利用 background-position 属性改变图像在背景中的位置。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">body</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background-image</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-function" style="box-sizing: border-box;">url(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/img/bg_03.png'</span>)</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background-repeat</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">no-repeat</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background-position</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">50</span>px <span class="hljs-number" style="box-sizing: border-box;">100</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>3. 缩进文本 （text-indent）
把 Web 页面上的段落的第一行缩进，这是一种最常用的文本格式化效果。
CSS 提供了 text-indent 属性，该属性可以方便地实现文本缩进。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">p</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">text-indent</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">5</span>em</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>同时也可用做文本信息隐藏（-99999px）
4. 字（单词）间隔 （word-spacing）
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">p</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.spread</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">word-spacing</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">30</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>5. 字母间隔（letter-spacing）
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">h1</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">letter-spacing</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> -<span class="hljs-number" style="box-sizing: border-box;">2</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>6. 字符大小写转换（text-transform）
none（默认无操作）uppercase（全大写）lowercase（全小写）capitalize（首字母大写）<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">h1</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">text-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> uppercase</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>7. 处理空白符（white-space）
1. 值 nowrap（防止元素中的文本换行）
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">p</span><span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">white-space</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> nowrap</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>2. 单行文本溢出显示 …（text-overflow）
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">span</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">overflow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> hidden</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">white-space</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> nowrap</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">text-overflow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> ellipsis</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>8. table 表格（border-collapse 单一边框）
border-collapse 属性设置是否将表格边框折叠为单一边框：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">table</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-collapse</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">collapse</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">table</span>,<span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">th</span>, <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">td</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">1</span>px solid black</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>9. 选择子元素（>）
如果您不希望选择任意的后代元素，而是希望缩小范围，只选择某个元素的子元素，请使用子元素选择器（Child selector）。
例如，如果您希望选择只作为 h1 元素子元素的 strong 元素，可以这样写：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">h1</span> > <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">strong</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>这个规则会把第一个 h1 下面的两个 strong 元素变为红色，但是第二个 h1 中的 strong 不受影响：
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">h1</span>></span>This is <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">strong</span>></span>very<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">strong</span>></span> <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">strong</span>></span>very<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">strong</span>></span> important.<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">h1</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">h1</span>></span>This is <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span>really <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">strong</span>></span>very<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">strong</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span> important.<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">h1</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>
10. 选择相邻兄弟 （＋）
如果需要选择紧接在另一个元素后的元素，而且二者有相同的父元素，可以使用相邻兄弟选择器（Adjacent sibling selector）。
例如，如果要增加紧接在 h1 元素后出现的段落的上边距，可以这样写：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">h1</span> + <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">p</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">margin-top</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">50</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>11. 伪类 (Pseudo-classes)
CSS 伪类用于向某些选择器添加特殊的效果。
1. 锚伪类
在支持 CSS 的浏览器中，链接的不同状态都可以不同的方式显示，这些状态包括：活动状态，已被访问状态，未被访问状态，和鼠标悬停状态。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">a</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:link</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-hexcolor" style="box-sizing: border-box;">#FF0000</span></span></span></span>} <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* 未访问的链接 */</span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">a</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:visited</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-hexcolor" style="box-sizing: border-box;">#00FF00</span></span></span></span>} <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* 已访问的链接 */</span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">a</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:hover</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-hexcolor" style="box-sizing: border-box;">#FF00FF</span></span></span></span>} <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* 鼠标移动到链接上 */</span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">a</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:active</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-hexcolor" style="box-sizing: border-box;">#0000FF</span></span></span></span>} <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* 选定的链接 */</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>2. CSS2 - :first-child 伪类（第一个子元素）
可以使用 :first-child 伪类来选择元素的第一个子元素。
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">type</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"text/css"</span>></span><span class="css" style="box-sizing: border-box;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">p</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:first-child</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">font-weight</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">bold</span></span></span>}</span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">p</span>></span>I am a <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span>strong<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span> man. I am a <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span>strong<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span> man.<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">p</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">p</span>></span>I am a <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span>strong<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span> man. I am a <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span>strong<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">em</span>></span> man.<span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">p</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>3. :first-line 伪元素（首行）
“first-line” 伪元素用于向文本的首行设置特殊样式。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">p</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:first-line</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-hexcolor" style="box-sizing: border-box;">#ff0000</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">font-variant</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">small-caps</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>“first-line” 伪元素只能用于块级元素。
4. :first-letter 伪元素（首字母）
“first-letter” 伪元素用于向文本的首字母设置特殊样式：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">p</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:first-letter</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-hexcolor" style="box-sizing: border-box;">#ff0000</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">font-size</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">xx-large</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>5. CSS2 - :before 伪元素
“:before” 伪元素可以在元素的内容前面插入新内容。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">h1</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:before</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">content</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-function" style="box-sizing: border-box;">url(logo.gif)</span></span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>6. CSS2 - :after 伪元素
“:after” 伪元素可以在元素的内容之后插入新内容。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">h1</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:after</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">content</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-function" style="box-sizing: border-box;">url(logo.gif)</span></span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>12. 使用 margin 属性来水平对齐
可通过将左和右外边距设置为 “auto”，来对齐块元素。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.center</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">margin-left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">auto</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">margin-right</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">auto</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">70</span>%</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background-color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-hexcolor" style="box-sizing: border-box;">#b0e0e6</span></span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>13. 改变光标 （cursor:pointer）
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">span</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.pointer</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">cursor</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">pointer</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">span</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.crosshair</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">cursor</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">crosshair</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">span</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.help</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">cursor</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">help</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">span</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.wait</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">cursor</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">wait</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>14. 透明度 （opacity）
定义透明效果的 CSS3 属性是 opacity。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">img</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">opacity</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">0.4</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">filter</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-function" style="box-sizing: border-box;">alpha(opacity=<span class="hljs-number" style="box-sizing: border-box;">40</span>)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* 针对 IE8 以及更早的版本 */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>IE9, Firefox, Chrome, Opera 和 Safari 使用属性 opacity 来设定透明度。opacity 属性能够设置的值从 0.0 到 1.0。值越小，越透明。
IE8 以及更早的版本使用滤镜 filter:alpha(opacity=x)。x 能够取的值从 0 到 100。值越小，越透明。
15. 颜色透明（RGBA）
<code class="hljs http has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">rgba(0, 0, 0, 0.6) ;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>
二、Css3 新特性
CSS3 标准
W3C 仍然在对 CSS3 规范进行开发。
不过，现代浏览器已经实现了相当多的 CSS3 属性。
１. CSS3 圆角边框（border-radius）
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">text-align</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">center</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">2</span>px solid <span class="hljs-hexcolor" style="box-sizing: border-box;">#a1a1a1</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">25</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-border-radius</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">25</span>px</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* 老的 Firefox */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>2. CSS3 边框阴影（box-shadow）
语法：box-shadow: h-shadow v-shadow blur spread color inset;
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">300</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">height</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">100</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background-color</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-hexcolor" style="box-sizing: border-box;">#ff9900</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">10</span>px <span class="hljs-number" style="box-sizing: border-box;">10</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-hexcolor" style="box-sizing: border-box;">#888888</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* 老的 Firefox */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">box-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">10</span>px <span class="hljs-number" style="box-sizing: border-box;">10</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-hexcolor" style="box-sizing: border-box;">#888888</span></span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>3. CSS3 文本阴影（text-shadow）
您能够规定水平阴影、垂直阴影、模糊距离，以及阴影的颜色：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">h1</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">text-shadow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-number" style="box-sizing: border-box;">5</span>px <span class="hljs-hexcolor" style="box-sizing: border-box;">#FF0000</span></span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>4. CSS3 自动换行（word-wrap）
在 CSS3 中，word-wrap 属性允许您允许文本强制文本进行换行 - 即使这意味着会对单词进行拆分。
允许对长单词进行拆分，并换行到下一行：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">p</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">word-wrap</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">break-word</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>5. CSS3 字体（@font-face）
使用您需要的字体
在新的 @font-face 规则中，您必须首先定义字体的名称（比如 myFirstFont），然后指向该字体文件。
如需为 HTML 元素使用字体，请通过 font-family 属性来引用字体的名称 (myFirstFont)：
<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span><span class="css" style="box-sizing: border-box;"> <span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">font-face</span></span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">font-family</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myFirstFont</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">src</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">url(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Sansation_Light.ttf'</span>)</span>, <span class="hljs-function" style="box-sizing: border-box;">url(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'Sansation_Light.eot'</span>)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* IE9+ */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">font-family</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">myFirstFont</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">style</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>6. CSS3 2D 转换
Internet Explorer 10、Firefox 以及 Opera 支持 transform 属性。
Chrome 和 Safari 需要前缀 -webkit-。
注释：Internet Explorer 9 需要前缀 -ms-。
通过 CSS3 转换，我们能够对元素进行移动、缩放、转动、拉长或拉伸。
1. translate()方法 （位置移动）
通过 translate() 方法，元素从其当前位置移动，根据给定的 left（x 坐标） 和 top（y 坐标） 位置参数：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">translate(<span class="hljs-number" style="box-sizing: border-box;">50</span>px,<span class="hljs-number" style="box-sizing: border-box;">100</span>px)</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-ms-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">translate(<span class="hljs-number" style="box-sizing: border-box;">50</span>px,<span class="hljs-number" style="box-sizing: border-box;">100</span>px)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* IE 9 */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">translate(<span class="hljs-number" style="box-sizing: border-box;">50</span>px,<span class="hljs-number" style="box-sizing: border-box;">100</span>px)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari and Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">translate(<span class="hljs-number" style="box-sizing: border-box;">50</span>px,<span class="hljs-number" style="box-sizing: border-box;">100</span>px)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">translate(<span class="hljs-number" style="box-sizing: border-box;">50</span>px,<span class="hljs-number" style="box-sizing: border-box;">100</span>px)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>2. rotate()方法（顺时针旋转角度）
通过 rotate() 方法，元素顺时针旋转给定的角度。允许负值，元素将逆时针旋转。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotate(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg)</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-ms-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotate(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* IE 9 */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotate(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari and Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotate(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotate(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>3. scale() 方法（改变尺寸）
通过 scale() 方法，元素的尺寸会增加或减少，根据给定的宽度（X 轴）和高度（Y 轴）参数：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">scale(<span class="hljs-number" style="box-sizing: border-box;">2</span>,<span class="hljs-number" style="box-sizing: border-box;">4</span>)</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-ms-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">scale(<span class="hljs-number" style="box-sizing: border-box;">2</span>,<span class="hljs-number" style="box-sizing: border-box;">4</span>)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* IE 9 */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">scale(<span class="hljs-number" style="box-sizing: border-box;">2</span>,<span class="hljs-number" style="box-sizing: border-box;">4</span>)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">scale(<span class="hljs-number" style="box-sizing: border-box;">2</span>,<span class="hljs-number" style="box-sizing: border-box;">4</span>)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">scale(<span class="hljs-number" style="box-sizing: border-box;">2</span>,<span class="hljs-number" style="box-sizing: border-box;">4</span>)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>值 scale(2,4) 把宽度转换为原始尺寸的 2 倍，把高度转换为原始高度的 4 倍。
4. skew() 方法（元素翻转角度）
通过 skew() 方法，元素翻转给定的角度，根据给定的水平线（X 轴）和垂直线（Y 轴）参数：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">skew(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg,<span class="hljs-number" style="box-sizing: border-box;">20</span>deg)</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-ms-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">skew(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg,<span class="hljs-number" style="box-sizing: border-box;">20</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* IE 9 */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">skew(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg,<span class="hljs-number" style="box-sizing: border-box;">20</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari and Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">skew(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg,<span class="hljs-number" style="box-sizing: border-box;">20</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">skew(<span class="hljs-number" style="box-sizing: border-box;">30</span>deg,<span class="hljs-number" style="box-sizing: border-box;">20</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>值 skew(30deg,20deg) 围绕 X 轴把元素翻转 30 度，围绕 Y 轴翻转 20 度。
5. matrix() 方法（2D 转换方法组合）
matrix() 方法需要六个参数，包含数学函数，允许您：旋转、缩放、移动以及倾斜元素。
7. CSS3 3D 转换
Internet Explorer 10 和 Firefox 支持 3D 转换。
Chrome 和 Safari 需要前缀 -webkit-。
Opera 仍然不支持 3D 转换（它只支持 2D 转换）。
1. rotateX() 方法（X 轴旋转）
通过 rotateX() 方法，元素围绕其 X 轴以给定的度数进行旋转。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotateX(<span class="hljs-number" style="box-sizing: border-box;">120</span>deg)</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotateX(<span class="hljs-number" style="box-sizing: border-box;">120</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotateX(<span class="hljs-number" style="box-sizing: border-box;">120</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>2. rotateY() 方法（Y 轴旋转）
通过 rotateY() 方法，元素围绕其 Y 轴以给定的度数进行旋转。
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotateY(<span class="hljs-number" style="box-sizing: border-box;">130</span>deg)</span></span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotateY(<span class="hljs-number" style="box-sizing: border-box;">130</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transform</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-function" style="box-sizing: border-box;">rotateY(<span class="hljs-number" style="box-sizing: border-box;">130</span>deg)</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>8. CSS3 过渡（transition）
CSS3 过渡是元素从一种样式逐渐改变为另一种的效果。
1. transition: width
应用于宽度属性的过渡效果，时长为 2 秒：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox 4 */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-pseudo" style="color: rgb(0, 0, 0); box-sizing: border-box;">:hover</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">300</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul>2. width 2s, height 2s, transform 2s（多项改变）
如需向多个样式添加过渡效果，请添加多个属性，由逗号隔开：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">2</span>s, height <span class="hljs-number" style="box-sizing: border-box;">2</span>s, transform <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">2</span>s, height <span class="hljs-number" style="box-sizing: border-box;">2</span>s, -moz-transform <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">2</span>s, height <span class="hljs-number" style="box-sizing: border-box;">2</span>s, -webkit-transform <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">2</span>s, height <span class="hljs-number" style="box-sizing: border-box;">2</span>s,-o-transform <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>所有的转换属性
3. 使用所有过渡属性
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transition-property</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transition-duration</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">1</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transition-timing-function</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> linear</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transition-delay</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox 4 */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transition-property</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">width</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transition-duration</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">1</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transition-timing-function</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">linear</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transition-delay</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transition-property</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">width</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transition-duration</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">1</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transition-timing-function</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">linear</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transition-delay</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transition-property</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">width</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transition-duration</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">1</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transition-timing-function</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">linear</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transition-delay</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li></ul>4. 简写的 transition （property，duration，timing-function，delay）
属性的名称，花费的时间，时间曲线，何时开始
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> width <span class="hljs-number" style="box-sizing: border-box;">1</span>s ease <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox 4 */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">width <span class="hljs-number" style="box-sizing: border-box;">1</span>s ease <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari and Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">width <span class="hljs-number" style="box-sizing: border-box;">1</span>s ease <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-transition</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">width <span class="hljs-number" style="box-sizing: border-box;">1</span>s ease <span class="hljs-number" style="box-sizing: border-box;">2</span>s</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>9. CSS3 动画
通过 CSS3，我们能够创建动画，这可以在许多网页中取代动画图片、Flash 动画以及 JavaScript。
CSS3 @keyframes 规则
如需在 CSS3 中创建动画，您需要学习 @keyframes 规则。
@keyframes 规则用于创建动画。在 @keyframes 中规定某项 CSS 样式，就能创建由当前样式逐渐改为新样式的动画效果。
1. 关键字 “from”“to”
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">keyframes</span> myfirst</span>{ <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">from</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">to</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">-moz-keyframes</span> myfirst </span>{ <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">from</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">to</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">-webkit-keyframes</span> myfirst </span>{ <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">from</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">to</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">-o-keyframes</span> myfirst </span>{ <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">from</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> <span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">to</span> <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li></ul>通过规定至少以下两项 CSS3 动画属性，即可将动画绑定到选择器：
1. 规定动画的名称
2. 规定动画的时长
把 “myfirst” 动画捆绑到 div 元素，时长：5 秒：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span> <span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">animation</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myfirst <span class="hljs-number" style="box-sizing: border-box;">5</span>s</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-animation</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myfirst <span class="hljs-number" style="box-sizing: border-box;">5</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-animation</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myfirst <span class="hljs-number" style="box-sizing: border-box;">5</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-animation</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myfirst <span class="hljs-number" style="box-sizing: border-box;">5</span>s</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span><span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>2. 0% 和 100% 选择器
必须定义动画的名称和时长。如果忽略时长，则动画不会允许，因为默认值是 0。
您可以改变任意多的样式任意多的次数。
请用百分比来规定变化发生的时间，或用关键词 “from” 和 “to”，等同于 0% 和 100%。
0% 是动画的开始，100% 是动画的完成。
为了得到最佳的浏览器支持，您应该始终定义 0% 和 100% 选择器。
例：当动画为 25% 及 50% 时改变背景色，然后当动画 100% 完成时再次改变：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">keyframes</span> myfirst </span>{ 0% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 25% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 50% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> blue</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 100% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> green</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">-moz-keyframes</span> myfirst </span>{ 0% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 25% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 50% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> blue</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 100% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> green</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">-webkit-keyframes</span> myfirst </span>{ 0% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 25% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 50% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> blue</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 100% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> green</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera */</span><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">-o-keyframes</span> myfirst </span>{ 0% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 25% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 50% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> blue</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 100% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> green</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li></ul>3. 改变背景色和位置：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-at_rule" style="box-sizing: border-box;">@<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">keyframes</span> myfirst</span>{ 0% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">0</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">top</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">0</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 25% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> yellow</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">200</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">top</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">0</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 50% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> blue</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">200</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">top</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">200</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 75% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> green</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">0</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">top</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">200</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span> 100% <span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> red</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">left</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">0</span>px</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">top</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">0</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span>}浏览器兼容代码省略...</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>下面的表格列出了 @keyframes 规则和所有动画属性：
4. 使用所有动画属性
<code class="hljs scss has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;">div</span>{ <span class="hljs-attribute" style="box-sizing: border-box;">animation-name</span><span class="hljs-value" style="box-sizing: border-box;">: myfirst;</span> <span class="hljs-attribute" style="box-sizing: border-box;">animation-duration</span><span class="hljs-value" style="box-sizing: border-box;">: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">5</span>s;</span> <span class="hljs-attribute" style="box-sizing: border-box;">animation-timing-function</span><span class="hljs-value" style="box-sizing: border-box;">: linear;</span> <span class="hljs-attribute" style="box-sizing: border-box;">animation-delay</span><span class="hljs-value" style="box-sizing: border-box;">: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>s;</span> <span class="hljs-attribute" style="box-sizing: border-box;">animation-iteration-count</span><span class="hljs-value" style="box-sizing: border-box;">: infinite;</span> <span class="hljs-attribute" style="box-sizing: border-box;">animation-direction</span><span class="hljs-value" style="box-sizing: border-box;">: alternate;</span> <span class="hljs-attribute" style="box-sizing: border-box;">animation-play-state</span><span class="hljs-value" style="box-sizing: border-box;">: running;</span> 浏览器兼容代码省略...}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul>5. 使用简写的动画 animation 属性
动画的名称,一个周期所花费的秒,速度曲线,何时开始,播放的次数
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">animation</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myfirst <span class="hljs-number" style="box-sizing: border-box;">5</span>s linear <span class="hljs-number" style="box-sizing: border-box;">2</span>s infinite alternate</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox: */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-animation</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myfirst <span class="hljs-number" style="box-sizing: border-box;">5</span>s linear <span class="hljs-number" style="box-sizing: border-box;">2</span>s infinite alternate</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome: */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-animation</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myfirst <span class="hljs-number" style="box-sizing: border-box;">5</span>s linear <span class="hljs-number" style="box-sizing: border-box;">2</span>s infinite alternate</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Opera: */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-o-animation</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"> myfirst <span class="hljs-number" style="box-sizing: border-box;">5</span>s linear <span class="hljs-number" style="box-sizing: border-box;">2</span>s infinite alternate</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>10. CSS3 多列
通过 CSS3，您能够创建多个列来对文本进行布局 - 就像报纸那样！
1. CSS3 创建多列（column-count）
把 div 元素中的文本分隔为三列：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-column-count</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">3</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-column-count</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">3</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">column-count</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">3</span></span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>2. CSS3 规定列之间的间隔（column-gap）
规定列之间 40 像素的间隔：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-column-gap</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">40</span>px</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-column-gap</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">40</span>px</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari 和 Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">column-gap</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">40</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>3. CSS3 列规则（column-rule）
规定列之间的宽度、样式和颜色规则：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-column-rule</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">3</span>px outset <span class="hljs-hexcolor" style="box-sizing: border-box;">#ff0000</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-column-rule</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">3</span>px outset <span class="hljs-hexcolor" style="box-sizing: border-box;">#ff0000</span></span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari and Chrome */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">column-rule</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">3</span>px outset <span class="hljs-hexcolor" style="box-sizing: border-box;">#ff0000</span></span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>11. CSS3 用户界面
在 CSS3 中，新的用户界面特性包括重设元素尺寸、盒尺寸以及轮廓等。
1. CSS3 Resizing（可调整大小）
规定 div 元素可由用户调整大小：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">resize</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">both</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">overflow</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">auto</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>2. CSS3 Box Sizing
box-sizing 属性允许您以确切的方式定义适应某个区域的具体内容。
border 或 padding的数值计入父宽高内（意思为不会增加父容器宽度）。
规定两个并排的带边框方框：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">box-sizing</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">border-box</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-moz-box-sizing</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">border-box</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Firefox */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">-webkit-box-sizing</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">border-box</span></span>; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/* Safari */</span> <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">width</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">50</span>%</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">float</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);">left</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>3. CSS3 Outline Offset
outline-offset 属性对轮廓进行偏移，并在超出边框边缘的位置绘制轮廓。
规定边框边缘之外 15 像素处的轮廓：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="color: rgb(0, 0, 0); box-sizing: border-box;">div</span><span class="hljs-rules" style="box-sizing: border-box;">{ <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">border</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">2</span>px solid black</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">outline</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">2</span>px solid red</span></span>; <span class="hljs-rule" style="box-sizing: border-box;"><span class="hljs-attribute" style="box-sizing: border-box;">outline-offset</span>:<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 102, 102);"><span class="hljs-number" style="box-sizing: border-box;">15</span>px</span></span>;<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>三、编写 CSS 注意事项
1. 修饰选择器（尽量少用）
能写.nav{}就尽量不要写ul.nav{}。过分修饰选择器将影响性能，影响 class 复用性，会增加选择器私有度。这些都应当竭力避免的。
如果想描述我们规划的 class 作用范围，可以在选择器前加上注释，如下写法：
<code class="hljs css has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">/*ul*/</span><span class="hljs-class" style="box-sizing: border-box; color: rgb(155, 112, 63);">.nav</span><span class="hljs-rules" style="box-sizing: border-box;">{<span class="hljs-rule" style="box-sizing: border-box;">}</span></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>这样我们就能在不影响代码私有度的前提下获知 class 作用范围。
2. 布局（宽度和高度）
所有内部组件都不要声明宽度，而由其外层父容器块（格栅系统）来决定。理想情况下，格栅系统应当用百分比设定。
坚决不要声明高度。高度应当仅用于尺寸已经固定的东西，例如图片。在 p，ul，div 等元素上不应当声明高度。如果需要的话可以写 line-height，这个更加灵活。。
3. 简写（谨慎使用）
编写像
<code class="hljs scss has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-attribute" style="box-sizing: border-box;">background</span><span class="hljs-value" style="box-sizing: border-box;">:red;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>
这样的属性的确很省事，但是你这么写的意思其实是同时声明
<code class="hljs scss has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-attribute" style="box-sizing: border-box;">background-image</span><span class="hljs-value" style="box-sizing: border-box;">:none;</span><span class="hljs-attribute" style="box-sizing: border-box;">background-position</span><span class="hljs-value" style="box-sizing: border-box;">:top left;</span><span class="hljs-attribute" style="box-sizing: border-box;">background-repeat</span><span class="hljs-value" style="box-sizing: border-box;">: repeat;</span><span class="hljs-attribute" style="box-sizing: border-box;">background-color</span><span class="hljs-value" style="box-sizing: border-box;">:red;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>
最优应当改为
<code class="hljs scss has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-attribute" style="box-sizing: border-box;">background-color</span><span class="hljs-value" style="box-sizing: border-box;">:red;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li></ul>
类似的，像 margin:0; 这样的声明的确简洁清爽，但是还是应当尽量写清楚。如果你只是想修改底边边距，就要具体一些，写成 margin-bottom:0;。
简写虽然是好东西，但是注意切勿滥用。
4. ID（CSS 里坚决不要用 ID）
在 HTML 里 ID 可以用于 JS 以及锚点定位，但是在 CSS 里只要用 class，一个 ID 也不要用。
Class 的优势在于复用性，而且私有度也并不高。私有度非常容易导致问题，所以将其降低就尤为重要。ID 的私有度是 class 的 255 倍，所以在 CSS 中坚决不要使用。
5. 选择器（保持选择器简短高效）
- 结构复杂的选择器将会影响性能。（如
.sidebar h3 span{}为三层，.content ul p a{}是四层），层级越深浏览器的消耗就越大。选择器应当尽量简短，更好的办法是直接给你想要添加样式的元素直接添加一个 class。 - class 名则不应当过于简略，例如
.user-avatar就远比.usr-avt好。
6. !important（优先级高，一般情况不要用）
用 !important 提升优先级也可以，例如如果你要让某条规则一直生效的话，可以用.error{ color:red !important; }。
避免主动使用 !important。例如 CSS 写得很复杂时不要用它来取巧，要好好整理并重构之前的部分，保持选择器简短并且避免用 ID 将效果拔群。
7. 魔数与绝对定位（「凑巧有效果」的数字）
魔数（Magic Number）是指那些「凑巧有效果」的数字，这东西非常不好，缺乏拓展性。
例如 .dropdown-nav li:hover ul{ top:37px; } 把下拉菜单移动下来，远非良策，因为这里的 37px 就是个魔数。37px 会生效的原因是因为这时 .dropbox-nav 碰巧高 37px 而已。
这时你应该用 .dropdown-nav li:hover ul{ top:100%; }，也即无论 .dropbox-down 多高，这个下拉菜单都会往下移动 100%。
每当你要在代码中放入数字的时候，请三思而行。
8. Debugging（调试）
如果你要解决 CSS 问题的话，先把旧代码拿掉再写新的。如果旧的 CSS 中有问题的话，写新代码是解决不了的。
把 CSS 代码和 HTML 部分删掉，直到没有 BUG 为止，然后你就知道问题出在哪里了。
有时候写上一个 overflow:hidden 或者其它能把问题藏起来的代码的确效果立竿见影，但是 overflow 方面可能根本就没问题。所以要治本，而不是单纯治标。
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