Employ the style guide

I made the style guide (and the UI toolkit) a while back, and I've finally gotten around to using it. I've also made it so it uses a separate SCSS file for each controller, so specific styling for different views are separated and easier to manage/fix.

This was also a great opportunity to throw out a lot of old unused styling code.

Some things aren't styled properly, but they're related to tables, which I'll style properly once @oneohtrix is done with those.