This CSS Reference shows the basic syntax of a CSS rule; lists all standard CSS properties, pseudo-classes and pseudo-elements, @-rules, units, and selectors, all together in alphabetical order, as well as just the selectors by type and allows you to quickly access detailed information for each of them. It not only lists the CSS 1 and CSS 2.1 properties, but also is a CSS3 reference that links to any CSS3 property and concept standardized, or already stabilized. Also included is a brief DOM-CSS / CSSOM reference.

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

See also Mozilla CSS Extensions for Gecko-specific properties prefixed with -moz; and WebKit CSS Extensions for WebKit-specific properties. See Vendor-prefixed CSS Property Overview by Peter Beverloo for all prefixed properties.

Basic rule syntax

Be warned that any syntax error in a rule definition will invalidate the entire rule.

Style rules

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.


strong { color: red;}                        li:hover > ul { display: block; }

More about examples: #1, #2


As these have so many different structure-formats, see At-rule for syntax of the specific at-rule you want.

Keyword index



A complete list of selectors in the Selectors Level 3 specification.

CSS3 Tutorials

These small how-to pages describe new technologies appeared in CSS3, or in CSS2.1 but with low support until recently:



Major object types:

Important methods: