Board Thread:Support Requests - Getting Technical/@comment-24761405-20160524171845/@comment-24473195-20160525161743

You don't design it twice as Saftzie showed above. The only difference between "my version" and  Saftzie's one is that I added all inline css to Special:CSS. This makes it "more" portable because even people using the full desktop mode on a mobile device will get a reasonable experience.

You can see a discussion about that here.