animated-gradient-border-ring

A rotating sweep-gradient ring around a card, chip or button, built from a clipped box, a full-size gradient and an opaque inset surface parked on its middle — where the modifier order is the whole mechanism and no blend mode is involved — plus why the SrcIn-inside-an-offscreen-layer version of this cannot draw a ring, and what that layer costs. Use when the gradient covers the whole surface instead of the border,…