CSS, short for Cascading Style Sheets, is a language used to control the presentation of HTML and XML documents including colors, layout, and fonts.
Cascading Style Sheets (CSS) is a style sheet language used for describing the look and formatting of a document written in a markup language. While most often used to style web pages and interfaces written in HTML and XHTML, the language can be applied to any kind of XML document, including plain XML, SVG and XUL.
Via Wikipedia
Specification
- W3C: CSS homepage
- W3C: CSS2.1
- W3C: Web Content Accessibility Guidelines (WCAG)
- W3C: Media Queries
- W3C: Selectors Level 3
- List of other CSS standards (including various parts of CSS3)
