This test checks that using a modifier key does not make the element to stop matching :focus-visible.
If the element that says "Focused" has a red background, then the test result is a FAILURE.
Press the Ctrl key.
If the element keeps the green outline and has not a red background, then the test result is SUCCESS.
Focused

PASS ":focus-visible" should be a valid selector
PASS Ctrl key doesn't make an element to stop matching :focus-visible