Intercepts and overrides are your most powerful techniques for controlling Drupal site output. In this chapter, we covered how to intercept and override both the default Drupal CSS and the themeable functions and templates.

The technique requires an understanding of Drupal naming conventions and an appreciation for the hierarchies that dictate precedence. Proper use of the naming conventions will enable you to extensively customize Drupal's appearance.

This chapter also included a discussion of various alternative techniques for handling themeable functions, together with the advantages of each. Together with good planning, the step-by-step instructions should allow you to implement overrides of themeable functions in a variety of manners.