CSS

Cascading Style Sheets (short CSS), is a language that describes and attaches style to structured documents. This allows one to separate document structure and style information. This way, multiple documents can share the same style without the need of defining it over and over again. Documents are smaller and easier to mantain. Styles can be changed without the need of changing all documents. This are just some advantages. CSS can style any XML or HTML document. Using its powerful selectors, one describes which elements of the document a style should be applied to. Many aspects of the selected elements appearience can be influenced: Position, size, background, borders, colours, fonts, voice (yes, CSS can also influence how a document gets spoken by a speech synthesizer) and more. For different devices one can define seperate styles, so one can define a style for printing, but another one for screens. CSS 2 contained many features. CSS 2.1 removes some of them, contains corrections and important additions. One can consider CSS 2.1 as widely supported today. However, beginning from level 3, CSS is split up into modules which can be improved independently. They introduce a plethora of new features, many of them are already supported by popular browsers.