CSS selectorsEdit
This is not an exhaustive list of CSS selectors but it shows the basic patterns that are useful:
ID selectors
#foo: selects the element whose id is foo.
Example:
<div id="foo">hello world</div>
Class selectors
.bar: matches all elements whose class is bar.
h2.baz: matches all h2 elements whose class is baz.
Examples:
<p class="bar">hello world</p>
<h2 class="baz">hello world</h2>
Universal selectors
*: selects all elements on the page.
Adjacent selectors
h2 + h3: selects any h3 element which follows an h2
Child selectors
div.foo>div.bar: selects any div element of class bar that is an immediate child of a div element of class foo
Descendant selectors
div table: selects any table element that is a descendant of a div element; note that unlike the case of child selectors it need not be an immediate child.