The document discusses using the 960.gs CSS framework for Drupal theming. It provides an introduction to CSS frameworks and their benefits, including making development easier and more scalable. It then describes the basics of grid-based design and how 960.gs works with 12-column and 16-column grids. It shows some examples of common layouts and how to implement grid classes. Finally, it briefly discusses the NineSixty Drupal theme which implements 960.gs and the ns() function for generating grid classes.