Size of windows

[KennethS]

I was playing the game and took a brief break (I fell asleep), leaving the game running. When I went back to the game all of the windows had shrunken to the point they are almost unreadable. I have my nose right up to the screen and some it is almost readable. Any ideas what happened and how to fix it?

[Gwalben]

If you zoomed your browser, it can be fixed with Ctrl and +/-/0.