CSS hints

CSS aggregation

IE has a restriction on no more than 32 css files. To avoid errors, css aggregation must be turned on in /admin/settings/performance. This combines all the css files into one cached css file. This is good for performance and would be good even without the IE problem as it brings it all down to the user with one server interaction. It is large but cached by most browsers and hence not requested again as they move through other pages. One effect of the caching is that users do not see changes to css files unless Drupal is told to clear the cache. This occurs automatically under some obscure conditions, but is better done by visiting /admin/settings/performance and hitting the save page button (no need to change anything on the page) immediately after changing any of the css files. The users then see the new css aggregated file the next time they change or refresh a page.