Board Thread:Support Requests - Designing Your Wiki/@comment-38160672-20201024233323/@comment-9605025-20201025060629

First off, to minimize the risk of violating the customization policy, you should always restrict CSS to the right rail and the main article space unless absolutely necessary. Your current CSS will try to change literally everything; including parts of the page you aren't supposed to touch.

It is far easier to expand the the group of things impacted by CSS than it is to restrict it. Even if you stop if from applying to specific items on the page, those items may have sub-items that this CSS will still change unless you explicitly list each and every sub-item as well.