how to reduce sidebar

[4freebird]

The PlanMaker spreadsheet has a sidebar which occupies about 15% of the spreadsheet display. I would like to either reduce or eliminate the sidebar so more attention can be devoted to the spreadsheet. But I cannot find a button to do so. Can someone tell me how this can be done?

[sven-l]

There is no button. Hover with the mouse over the left (inner) edge of the sidebar and hold left mouse button pressed while you reduce or increase the size of the sidebar.