자꾸 까먹어서 포스팅하게됬다. . .
In CSS, pattern matching rules determine which style rules apply to elements in the document tree(‘돔트리’). These patterns, called selectors, may range from simple element names to rich contextual patterns. If all conditions in the pattern are true for a certain element, the selector matches the element.
The case-sensitivity of document language element names in selectors depends on the document language. For example, in HTML, element names are case- insensitive, but in XML they are case-sensitive.
The following table summarizes CSS 2.1 selector syntax:
PatternMeaningDescribed in section
* Matches any element.
Matches any E element (i.e., an element of type E).
Matches any F element that is a descendant of an E element.
E > F
Matches any F element that is a child of an element E.
Matches element E when E is the first child of its parent.
The :first-child pseudo-class
Matches element E if E is the source anchor of a hyperlink of which the target is not yet visited (:link) or already visited (:visited).
The link pseudo-classes
Matches E during certain user actions.
The dynamic pseudo-classes
Matches element of type E if it is in (human) language c (the document language specifies how language is determined).
The :lang() pseudo-class
E + F
Matches any F element immediately preceded by a sibling element E.
Matches any E element with the “foo” attribute set (whatever the value).
Matches any E element whose “foo” attribute value is exactly equal to “warning”.
Matches any E element whose “foo” attribute value is a list of space-separated values, one of which is exactly equal to “warning”.
Matches any E element whose “lang” attribute has a hyphen-separated list of values beginning (from the left) with “en”.
Language specific. (In HTML, the same as DIV[class~=”warning”].)
Matches any E element with ID equal to “myid”.