Introducing CSS

CSS is the W3C standard for defining the visual presentation for web pages. HTML was designed as a structural markup language, but the demands of users and designers encouraged browser manufacturers to support and develop presentation-oriented tags. These tags “polluted” HTML, pushing the language toward one of decorative style rather than logical structure. Its increasing complexity made life hard for web designers, and source code began to balloon for even basic presentation-oriented tasks. Along with creating needlessly large HTML files, things like font tags created web pages that weren’t consistent across browsers and platforms, and styles had to be applied to individual elements—a time-consuming process.

The concept behind CSS was simple, yet revolutionary: remove the presentation and separate design from content. Let HTML (and later XHTML) deal with structure, and use a separate CSS document for the application of visual presentation.