CSS “skin” files for specific graphic treatments
You may not want every page or section of your site to look the same. If so, you can add a third “skin” css file that provides specific graphics, colors, and header treatments for all pages in a site section that share the same visual design. Each css file in the multifile cascade adds information, moving from sitewide general layout and typographic styles to visual styles that may be specific to a few pages (fig. 5.6)