Board Thread:Support Requests - Designing Your Wiki/@comment-27494008-20180305094101/@comment-168424-20180309194824

Monobook is not officially supported. See Help:Layout.

You can affect the Monobook skin wiki-wide CSS by editing MediaWiki:Monobook.css on your wiki.

As always, please give a link to your wiki and be as specific as possible with what you want to change.