Click on your name in the top right corner
From the dropdown menu, select ‘Preferences’
Check or uncheck the option to ‘Turn On Fullscreen Document Mode’
How do I exit the fullscreen document view?
To exit the fullscreen mode, simply click the x in the top right corner or press the ESC button (only supported on some browsers).
I’m no longer in the fullscreen mode, but the document is oversized and I can’t find the x!
Hover your cursor over one of the document information headers and your cursor should change into a drag cursor with four outward arrows. Click, hold, and drag downwards to reveal the top of the document viewer. Press the x to exit the viewer. Watch the video below [starts at 0:15] for a demo.