Wiki markup is Geocities hideous. We're talking table-based layouts and deprecated HTML tags. Lucky for all of us, Wikimedia software plays nice with any CSS markup that will go inline. That basically the only limitations on what you can pull off are keyframes and what CSS3 browsers don't yet support. Most can handle vendor codes. Check out the Mozilla Developer Network for great CSS documents, including which browsers support which CSS3 markup. Wikimedia doesn't permit anchor or image tags, so you're limited to regular wikilinks and [[file:]] references.