Board Thread:Support Requests - Getting Started/@comment-27202257-20131208220641/@comment-11733175-20131208231136

is the correct selector to use, the reason it doesn't work is you have a syntax error in your wikia.css file.

You need to close the @media print like so: @media print { .navbox { display:none; } }

You're just missing a closing }, adding it in should fix the problem after the cache updates. You'll see an error message (the red x icon) at the bottom of the page when editing using Special:CSS saying something like Expected RBRACE at line ...