This chapter showed intercepts and overrides in action. We went from a basic theme design, to a more specialized variation of the theme with a new look and feel. We made the conversion in three steps: Theme configuration, CSS modifications, and Themeable Function modifications.
Drupal's consistent usage of orders of precedence and the ability to leverage cascades of style sheets are keys to the success of this approach to theme creation. The ability to intercept and override the styles and the themeable functions made it possible for us to start with one design and end with a very different one—without having to code from scratch.