Document Viewer can expand to fill your entire screen with its fullscreen mode. Fullscreen helps by utilizing maximum screen space on all device sizes and it's a great way to only focus on the document.
To view a document in fullscreen mode, click the floating Fullscreen icon on the lower left corner of the document viewer.
You can also use the zoom feature in Fullscreen mode to utilize the maximum screen space.
To exit fullscreen, move the mouse to the top of the window, click the Exit fullscreen icon when it appears on the screen. Alternatively, you can press ESC or F11 on the keyboard.