User blog comment:DaNASCAT/Technical Update: April 22, 2015/@comment-4864110-20150425045313/@comment-452-20150425172856

No. Go to Mediawiki:Wikia.css on the wiki where you want to fix it. Putting it in your global.css will only fix it for you, and will not fix it for other people viewing the wiki.

See Help:JavaScript_and_CSS_Cheatsheet for additional information.