On the Tags page, when there are no search results (e.g. if you search for
test2), the tag list shrinks, but there's still a white ribbon visible in the footer, giving the page a really weird look:
On closer look, there seems to be a problem with the ribbon on all pages, because it's one pixel on each side wider than the main content box.
Tested on three browsers (Safari, Firefox, Chrome) on macOS.