Code adapted to Houdini from https://codepen.io/ayamflow/pen/DqfBd

Note: This demo no longer works as expected. Not sure if bug. Related to global scope selection (paint worklets are not in sync) or code idempotency. Let me know if you can help!

CSS IS AWESOME
#el {
  border-image-source: paint(wobble, deeppink);
  border-image-slice: 0 fill;
  border-width: var(--border-width);
  border-image-outset: var(--border-width);
  --border-width: 50px;
}