Forum how do I edit the forum style?
 

I searched and couldn't find anything. When I go to the Style Manager (like in 3.x) and I go to edit the settings but all of them say "The following style options are obsolete and are available here for reference purposes only. Style options such as these can now be edited in the Style Variable Editor."

But I can't find a 'Style Variable Editor'? I must be missing something obvious.