User blog comment:Sannse/Important Updates on Wikia’s New Look/@comment-227331-20100929023755/@comment-8-20100929192658

You will still be able to add CSS to style templates and so on. Just add the code to Mediawiki.wiki.css (your personal css is also available as username/wikia.css ).

Common.css was breaking a lot of wikis (because of skin specific code in there), so we've moved some to the core code, and anything else useful can be moved to the new page. The same functionality is in place