CSS reference

Use this CSS reference to browse an alphabetical index of all the standard CSS properties, pseudo-classes, pseudo-elements, data types, and at-rules. You can also browse a list of all the CSS selectors organized by type and a list of key CSS concepts. Also included is a brief DOM-CSS / CSSOM reference.

Please see Mozilla CSS Extensions for Gecko-specific properties (prefixed with -moz). See WebKit CSS Extensions for WebKit-specific properties (mostly prefixed with -webkit).

Note that CSS rule definitions are entirely (ASCII) text-based, whereas DOM-CSS / CSSOM (the rule management system) is object-based.

Basic rule syntax

Style rule syntax

selectorlist {
  property: value;
  [more property:value; pairs]
}

... where selectorlist is: selector[:pseudo-class] [::pseudo-element] [, more selectorlists]

See selector, pseudo-element, pseudo-class lists below.

Style rule examples

strong {
  color: red;
}

div.menu-bar li:hover > ul {
  display: block;
}

For a beginner-level introduction to the syntax of CSS selectors, please see this tutorial. Be warned that any CSS syntax error in a rule definition invalidates the entire rule. Invalid rules are ignored by the browser.

At-rule syntax

As the structure of at-rules varies widely, please see At-rule to find the syntax of the specific one you want.

Keyword index