Animate this original artwork as a refined five-second website hero media asset. The exact iridescent glass spiral slowly rotates a few degrees as rainbow caustics move across its surface and floor. Preserve the spiral shape and central hollow, no melting. Preserve original identities, proportions, palette and materials. Locked camera unless explicitly specified. No zoom, cuts, text, UI, new objects or distorted anatomy. Continuous restrained motion; begin and end near the same composition where physically plausible.