Board Thread:Support Requests - Designing Your Wikia/@comment-3417079-20150611025545/@comment-5558012-20150611032057

You need to edit MediaWiki:Common.css as these are styling issues.

Spacing before and after is controlled by the line-height property so to add more spacing around h3 headers (three equal signs), you need something of this nature:

You can do the same with h4 and h5 as you see fit.