Create multi-point mesh gradients by stacking radial gradients.
background: $radial-gradient(at 20% 20%, #0ea5e9 0px, transparent 50%), radial-gradient(at 80% 30%, #ec4899 0px, transparent 50%), radial-gradient(at 30% 80%, #8b5cf6 0px, transparent 50%), radial-gradient(at 75% 75%, #f59e0b 0px, transparent 50%), #0f172a;