Depending on the element hovered the order of the elements changes with the display:flex; and order:-1; attributes. On hover the elements following in the DOM, not the view, unpause an animation fading out and alternating from 30% of the document width to 1% of the document width.

Firefox seems to register hover changes even when the mouse is kept motionless. Chromium in comparision seems to keep the hover unless the mouse moves, leading to a far calmer effect and more reliable second click.

Click again for a version that hightlights the element that currently is registered as :hover.