Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation semantics (the look and formatting) of a document.
Its most common application is to style web pages written in HTML and XHTML, but the language can also be applied to any kind
of XML document, including plain XML, SVG and XUL. CSS is designed primarily to enable the separation of document content from
document presentation, including elements such as the layout, colors, and fonts. This separation can improve content accessibility,
provide more flexibility and control in the specification of presentation characteristics, enable multiple pages to
share formatting, and reduce complexity and repetition in the structural content. CSS can also allow the
same markup page to be presented in different styles for different rendering methods, such as
on-screen, in print, by voice (when read out by a speech-based browser or screen reader)
and on Braille-based, tactile devices. It can also be used to allow the
web page to display differently depending on the screen size or
device on which it is being viewed.