The CSS Working Group has published CSS Basic User Interface Module Level 3 (CSS3 UI) as a W3C Recommendation. This specification describes user interface related properties and values that are proposed for CSS level 3 to style HTML and XML (including XHTML). It includes and extends user interface related features from the properties and values of CSS level 2 revision 1. It uses various properties and values to style basic user interface elements in a document. This specification is implemented in all modern browsers.
CSS is a language for describing the rendering of structured documents (such as HTML and XML) on screen, on paper, in speech, etc.