Thread:VisualEditor/Feedback/Modern skin support/reply (3)

How much work is hard to tell, but you would need to add something like http://git.wikimedia.org/blob/mediawiki%2Fextensions%2FVisualEditor/d64aa82c4a1436cb13995729c390906c67235117/modules%2Fve-mw%2Finit%2Fstyles%2Fve.init.mw.ViewPageTarget-monobook.css

But then modern specific instead of mono book specific.

And then register that one the root VisualEditor.php file.