It is possible to close all of the tabs and all of the docks in a Congo, leaving you with something like this:
The Live and Main Playback tabs are normally locked from closing so one would need to manually unlock them for this to happen.
However, if you do this, in some cases the facepanel buttons may no longer open their corresponding tabs, and obviously you can't quit because Exit is in the Browser!
To reset the screens back to the Default Layout: (Browser & Effects docks, locked Main Playback & Live tabs)
In version 6.3.x and later, to open the Browser again: