Focus Mode
Hiding everything but the test case while you test.
Focus mode clears everything but the test case from the testing page, so you have more room to read and less to distract you.
On the testing page, select Focus Mode beside Testing Shortcuts, or press Ctrl/Cmd + Shift + F. The sidebar and page header are hidden, and the window is framed in a soft glow in the project's colour.
Everything else works as normal, including the keyboard shortcuts. To leave, select Exit Focus or press the shortcut again.