Emptying the screen
The Focus Mode button in the document header, orCmd/Ctrl + Shift + F11. The sidebar folds away, and the tab row, the document title, the formatting toolbar, and the AI panel disappear all at once. On macOS it goes full screen; on Windows it maximizes.
Esc gets you out. It does not listen while an IME is still composing a character, so finish the character and press again. The state you leave it in holds the next time you open the app.


Focus Mode. Only the body remains; the rest of the screen steps back.
Keeping only the paragraph you write
The Focus section under Settings → Editor holds two. Focus mode keeps only the block the cursor sits in and fades the rest. Select several paragraphs and every block the selection touches stays. Fade opacity runs from 5% to 90%, Blur from 0px to 8px. They start at 25% and 1.5px. Hover a number and a three-line preview shows the strength. Typewriter mode holds the line you are writing at the center of the screen. The two run separately, so you can turn on just one. You can turn them on from the gear at the right of the toolbar (Current File Settings) as well. Changed with a document open, it is your own setting for that document alone, so the screens of the people working with you stay as they were. The toolbar disappears in Focus Mode, so set it beforehand.

The Focus section. Match the blur strength by eye with the preview.
Measuring time
The clock button at the right of the header is the timer. Expanded is the default, so the time left shows as numbers; switch to Compact and only the turning-hand icon remains. Press to open it and three presets appear (5m, 30m, and 50m at first). Choose one and press Start. While it runs the buttons are Pause and Resume; once it is done they become Stop and Restart. It sounds when it ends. Settings in the popover changes the values. Timer Presets (min) is always three, each between 1 and 120 minutes. Set Timer Mode to Stopwatch and it does not run backwards; the time you sit adds up instead. Turn on Show Floating Widget and a small window appears at the bottom right, which you drag wherever you want. In Focus Mode neither the header button nor the widget is visible. The timer still runs and still sounds when it ends, so you can time a stretch with the screen emptied.

The timer popover. Choose a preset and press Start.