Using Zen Mode
Zen Mode is a distraction-free writing environment that lets you focus solely on the page. It hides the main toolbar, the status bar, the page tabs, and the side panels — leaving just you and the script.
Entering and leaving
Choose View ▸ Enter Zen Mode or press F6. To leave, do the same — the menu item flips to Exit Zen Mode while you're in it.
Going fully bare
Zen Mode keeps the floating element toolbar so formatting stays within reach. For a truly bare page, turn that off too with ⌘L / Ctrl+L. While you're in Zen Mode the other toolbar toggles leave the View menu, so the hotkey is the way to do it.
Zoom still works in Zen Mode — ⌘= / ⌘- / ⌘0 to zoom in, out, or back to actual size.