CSS

Separate style from content

CSS, or Cascading Stylesheets is a language for styling websites.

It is most commonly used for styling HTML or XHTML elements in web browsers, though it can also be used to style 'raw' XML.

For example, many Firefox extensions use CSS to style their own elements.

Modern HTML / XHTML ought to describe the content that it contains, whereas CSS sets colours, layout and typographical rules. It can be used to replace text with graphics or to make elements semi-transparent.

Future versions of CSS may allow animation rules to be set.