Fix issues with specificity order in Vanilla

Follow up to Stylelint migration #3010

Stylelint default rules enforce following specificity order in the code.
In most places we do comply with this, others were simple to fix, but there are some parts of the code that fail on that and are not easy to fix.

Currently we have this rule set up as warning, but it's unnecessary showing up in the stylelint output, and recently also starts to show up in ALL pull requests due to GH new feature of showing annotations from GitHub actions.

We should try to fix these files to make them comply to specificity order or disable this rule in the sections that can't be fixed.

Start by reviewing the Vanilla styles and the Stylelint specificity-order warnings referenced in the issue. Identify the affected sections, then either bring their declarations into the required order or disable the rule only where fixing is not practical; done means the unnecessary warnings no longer appear in Stylelint or GitHub Actions output.

Written by the indexing model from the issue text.