Chapter 4. Style Sheets and Themeable Functions

All of the HTML output in Drupal comes from various functions, many of which are themeable. The styling of the output is controlled by various style sheets. Accordingly, the key to controlling your site's look and feel is a good command of the themeable functions and the style sheets.

The Drupal system contains a large number of style sheets and an even greater number of themeable functions. In this chapter, we'll take you on a guided tour of all the various style sheets and themeable functions, as a precursor to learning how to intercept and override these elements in the course of customizing your themes.

A Guide to Drupal Style Sheets

A typical Drupal installation will include twenty style sheets, and may also include a certain number of embedded styles. If you have installed additional extensions, you may well find that they come with their own style sheets, pushing the count up even higher.

The Drupal approach to style sheets may initially...