Board Thread:Support Requests - Designing Your Wiki/@comment-33281220-20181004215159/@comment-9605025-20181005183658

Yes, unfortunately, it would be very hard to get Oasis to look like Vector. MonoBook, Uncyclopedia, and Vector convert MediaWiki markup into similar HTML. Because of that, it isn't too difficult to tweak CSS to make them look like each other. However, Oasis structures the HTML very differently. It could still technically be done but would require you to use JS to restructure the HTML of the page; which would be allowed for personal JS but not site JS.