CSS之margin

margin-top:上边距
margin-right:右边距
margin-bottom：底部边距
margin-left:左边距
margin：上右下左
margin相对于上一元素的left right top bottom

<div id="d1">#d1</div><div id="d2">#d2</div><div id="d3">#d3</div><div id="d4">#d4</div>

   <style type="text/css">     div{        width: 250px;        height: 100px;        border:5px solid #000000;        color: black;        font-weight: bold;        text-align: center;     }     div#d1{         background-color: red;     }     div#d2{        background-color: green;         margin-left: 15px;         margin-top:5px;     }     div#d3{        background-color: yellow;        margin-left: 75px;     }     div#d4{        background-color: blue;       margin-left: 250px;       margin-top: 25px;     }     </style>