Loose rivets, might it have something to do with personas you are using?
I'd never heard of these, and indeed a dark background makes the fine writing on the top menu visible - thanks for that.
However, I'd like to get the whole thing back to some kind of recognizable shape.
I've just got rid of the main menu and got the orange FF pop-down box back. Trouble is, it does not contain all the items on the simple File through to Help menu.