CSS: Separating Style From Structure

#The Font Tag Problem

By 1996, HTML had become a mess. Designers were using <font> tags, invisible tables, and spacer GIFs to control layout. Every visual change meant editing the HTML itself. Hakon Wium Lie and Bert Bos proposed CSS as a clean separation: HTML handles structure, CSS handles presentation.

body {
  font-family: Georgia, serif;
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.6;
}

#The Cascade

The “C” in CSS is its most powerful — and most confusing — feature. Styles cascade from browser defaults, to user stylesheets, to author stylesheets, with specificity determining which rule wins. This mechanism enables theming, responsive design, and the entire concept of design systems.