Reader / Zen mode

Cmd/Ctrl+. (or View → Toggle Reader Mode in the Command Palette) collapses the toolbar, sidebar, TOC, and status bar — leaving only the rendered preview centered at a comfortable reading width. Press the same shortcut to come back.

F11 is accepted as a fallback on platforms where it isn’t already taken by the OS. macOS Mission Control swallows F11 by default — use the period chord there.