Board Thread:Support Requests - Getting Technical/@comment-2026043-20121214164221/@comment-188432-20121214165415

It really depends on how your wiki is set up. Most wikis do find it convenient to have some code which is shared by Wikia and Monobook. This CSS resides in Common and then, yes, is manually imported into Wikia and Monobook. So if you want to share CSS between the two skins, you do need to manually import it.

However, it's equally possible to have the two skins completely separately designed. That might be more work, depending on your stylistic requirements, but it has a certain appeal, too. It would mean that you wouldn't need to at all depend upon a manual import, and would almost certainly make pages load faster. It would certainly mean you'd be less susceptible to hiccups in the page-loading process that would temporarily rob your wiki of some formatting while it waited for Common to load up.