On Xfce, that very usefully magnifies the window content in analog fashion. That's an alternative to the discrete action of ^+/^-.

CTRL+ALT+RightArrow, as described by alexus, is hard to beat for convenience too, I think.

Useful stuff, all. And I knew none of it. (Tending to use the GUI just to run a bunch of xterms, a browser, and sometimes kicad.)

Erik

P.S. Will have to upgrade my ancient devuan, and get off this web mail monstrosity, now that an owner-build, a renovation & sale, and an off-grid solar installation have been knocked off the to-do list.