Board size on screen adjustment

How can I reduce the displayed board width by 1/2 so I can get it all in on my screen?
Rob

@RobWright, on the screen you are displaying a board, click your username, then click board geomenty and move the bar in adjust board size.

If you are on mobile, tap the bottom right hand corner, and move diagonally up right.
EDIT: Actually I don't think that works on mobile :(