probably more subversive to drop arXiv''s existing content into an instance of GitHub and conform the user interface to the existing arXiv U/I. Or, actually, just keep the colors and stick with Github's UI.
Github UI? Before forcing everything to look like github, please, please, remember the term "user experience research". Github UI has major issues and they keep improving. If every open website has a github UI, that's gon to be like seeing every website running default bootstrap interface. No.