No. 3 on the Top Pens of 2023 is "Glowy Hover Effect" by Ines.
Such a clever tactic to duplicate the DOM in a layer directly on top, make coloring adjustments, then mask it to only show a portion of it.
https://codepen.io/inescodes/pen/PoxMyvX

https://twitter.com/CodePen/status/1749542258569806064