Not really a bug but please add one pixel of padding right/bottom to the content border div class.
Imgur
See the link for before/after. (Well, actually the pics are uploaded in backwards order!)
The .content-border has a padding of 4 pixels. But with top/left border gray and right/bottom white, it looks weird. If you make right/bottom have 1 more pixel extra padding, it looks better. Right now, it looks like there is actually less padding on the right/bottom! ANNOYING!
You can see the change from padding: 4px; to padding: 4px 5px 5px 4px; highlighted in the inspector tool. You can see the change in the notification boxes, and also in the black/dark area where there is a region selector dropdown.
Riot please fix.
Thanks.