Flock — the sign-up screen whose logo lights up under the cursor

A full-viewport, never-scrolling auth hero on warm near-black. On the left a two-line headline, three SSO pills, a floating-label field, and a submit that goes brand-orange the instant you type. On the right the brand mark sits almost black until a soft light, tracking the cursor across the whole viewport rather than only the logo, sweeps over it and reveals the real thing rim first. Three CSS mask layers over one PNG, plus a QR card whose dot radius turns out to be a decode constraint and not a style choice. English copy throughout. Free example, live demo included.

The prompt copies to your clipboard — the demo above is what it builds.