css 标签格式

PatternMeaningFirst Defined in CSS LevelEAn element of type E1E:linkan E element being the source anchor of a hyperlink of which the target is not yet visited (:link) or already visited1E:activean E element during certain user actions1E::first-linethe first formatted line of an E element1E::first-letterthe first formatted letter of an E element1E.warningan E element whose class is "warning" (the document language specifies how class is determined).1E#myidan E element with ID equal to "myid".1E Fan F element descendant of an E element1*Any element2E[foo]an E element with a "foo" attribute2E[foo="bar"]an E element whose "foo" attribute value is exactly equal to "bar"2E[foo~="bar"]an E element whose "foo" attribute value is a list of whitespace-separated values, one of which is exactly equal to "bar"2E[foo|="en"]an E element whose "foo" attribute has a hyphen-separated list of values beginning (from the left) with "en"2E:first-childan E element, first child of its parent2E:lang(fr)an element of type E in language "fr" (the document language specifies how language is determined)2E::beforegenerated content before an E element2E::aftergenerated content after an E element2E > Fan F element child of an E element2E + Fan F element immediately preceded by an E element2E[foo^="bar"]an E element whose "foo" attribute value begins exactly with the string "bar"3E[foo$="bar"]an E element whose "foo" attribute value ends exactly with the string "bar"3E[foo*="bar"]an E element whose "foo" attribute value contains the substring "bar"3E:rootan E element, root of the document3E:nth-child(n)an E element, the n-th child of its parent3E:nth-last-child(n)an E element, the n-th child of its parent, counting from the last one3E:nth-of-type(n)an E element, the n-th sibling of its type3E:nth-last-of-type(n)an E element, the n-th sibling of its type, counting from the last one3E:last-childan E element, last child of its parent3E:first-of-typean E element, first sibling of its type3E:last-of-typean E element, last sibling of its type3E:only-childan E element, only child of its parent3E:only-of-typean E element, only sibling of its type3E:emptyan E element that has no children (including text nodes)3E:targetan E element being the target of the referring URI3E:enableda user interface element E which is enabled3E:disableda user interface element E which is disabled3E:checkeda user interface element E which is checked (for instance a radio-button or checkbox)3E:not(s)an E element that does not match simple selector s3E ~ Fan F element preceded by an E element3