Thread:Project:Support desk/Should I use MediaWiki for my project?/reply (3)

A grouping or listing of pages is possible, if you put them in Categories. That basically allows you to create a kind of category tree: Main categories, sub-categories, (sub-subcategories if you like, ...) and then the actual pages.

For CSS it depends: If you say you basically want to use the Vector skin, then you can simply add some lines of CSS to the wiki page MediaWiki:Vector.css in your wiki. However, if you basically want to have another, an own skin, then you should add an own skin with its own files in the filesystem and then you can (you better should) add the CSS in these skin files directly.