Fix up CSS, especially for mobile

At some point soon, get @keegan to fix up CSS on the https://www.pfaffmanager.com/pfaffmanager/servers/:id page.

Maybe turn off the help stuff for mobile, but at least make it show up below. Also mobile is too wide (horizontal scrolls), I think even on category and topic pages.

Consider moving the theme stuff keegan did in the theme into the plugin, so it’ll be easier to see/test in development.