User blog comment:Sannse/Your First Look at the New Wikia/@comment-1430834-20100904021824/@comment-417287-20100904085453

The file you linked to is SCSS not CSS. SCSS is super sassy, and not the type you can use on your local wiki. And ya, they made a change recently so the name is MediaWiki:Wikia.css over mw:oasis.css