Click anywhere on the screen or press any key to toggle the <div> between hidden and showing.

This is a <div> element that transitions between display: none; opacity: 0 and display: block; opacity: 1. Neat, huh?

This is another paragraph to show that display: none; is being applied and removed on the above <div> . If only its opacity was being changed, it would always take up the space in the DOM.