Useless Things Series: Brightness Overlay with Slider
Add an overlay to the entire webpage with a brightness slider positioned at the center below the screen. The brightness or slider Appear and Disappear when 'b' or 'c' is clicked.
When pressing 'b' the overlay with the slider appears and disappears. But when 'c' is clicked it makes the slider appear and disappear, it also automatically disappears after the set time.
