I recently had a need for a timer/revert icon that can animate forward and backward.
I wanted it to be a purely CSS and HTML versus an animated SVG or GIF so it can be manipulated more easily in the browser.
The size of the icon is relative to the wrapper so setting a different font-size will scale the icon proportionally.
Animation in Multiple Directions
The icon needs to animate forward and backward as well as have a rest state. The animation uses CSS keyframes based on the classes, 'forward' and 'backward'.