Styling a menu in the colophone widget (page bottom)

Hi there! Thanks, Emil, for such an eye-catching theme!

I am preparing a website for a colleague who is a beginner in WordPress and editing webpage contents and have an issue I cannot resolve easily.

I have created separate menus for top, main and submenu and they look great.
Another menu I have placed in a widget at the bottom of the page, in the colophon widget area – and this one is not styled optimally: see the problem, and my CSS.

I am trying to obtain non-contrasting effect similar to a thin menu I’ve made on my own, but I don’t want to force the colleague to code HTML, so ability to use a WordPress menu is importand to me.

It might be with a white background as the submenu, or just as it is, but without the gray bar next to menu items.
The problems are: letters are blurred and background when hovered has a color too similar to the letters.

Could I please ask for some help or a hint? Am I selecting proper elements? Maybe it could become a part of the Responsive stylesheet itself? Thanks in advance.