You should see no red rectangles or squares before or during the text
Below, you should see two horizontal green rectangles, side by side
Click the
Go full screen
button below
The page should enter full screen mode, with only a green square being visible.
The browser might display a permission window asking you to allow full screen on this page. Allow it.
Exit full screen (e.g. by pressing
Esc
)
The two green rectangles should be visible, along with all the other initial content.
Go full screen
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