Style fixes for recent jars, the search page, and the browse page

This should make the dashboard/search/browse pages look a little better on mobile and in general. There's still plenty to do, but I think this is a good start.
Sure, updated in a854c5086c124b564e5b8c42cd287ee4e7a2e8ea. I hadn't read a style guide yet, just wanted to make it clear that that was a constant.