This happens all the time to me, do not be alarmed.
Just press Alt + Q When you are in the messed up starcraft view and you can still type. That should bring you to the login screen, but you can not see it.
Now press Alt + Tab and then click on the starcraft icon in your taskbar at the bottom.
Voila! Login and you're finished!
If you have already pressed Alt + Tab, and it is still messed up screen (before you log out), click on the starcraft icon at the bottom and it will look about the same, Log out and alt + tab. There
