Iridescent sweep border

A single rainbow arc runs the perimeter of a card on a 4.2 s lap, leaving a hairline in the panel’s own colour behind it. One conic gradient, one registered angle, no JavaScript.

What it is

A single band of rainbow light runs around the edge of a card, over and over, leaving a plain hairline behind it. It is the outline you see on AI products, crypto dashboards and premium upgrade panels — the cheapest way to say 'this one is special' without adding a badge or changing the layout. Because the whole thing is one gradient and one rotating angle, it costs nothing to run and works on any card, button or modal you already have.

Full library — live sample, numbers, prompt and source — is for clients. I have the password

Seen in

Douyin @跟着学姐学AI · ep.34 “如何让 AI 生成五种粒子边框动效” · effect 01/05 · 0:04–0:06 (3× playback)