Board Thread:Support Requests - Designing Your Wiki/@comment-5441589-20190902132258/@comment-9605025-20190902214830

It depends. The example I provided will be applied to the "border" of all users' pages. If you want it on yours only, we need to make some modifications. Where you place the CSS depends on who you want to see the changes. If you want all viewers of your wiki to see the changes, then use MediaWiki:Wikia.css. If you want the changes just for yourself on your wiki, use wikia.css. If you want the changes just for yourself but for all wikis, use global.css.