Loading Shimmer
A slanted beam that travels left to right — stacked like a border glow, painted as a fill.
In use
Configurator
Bloom, beam, and core are stacked radial ellipses — not one gradient.
Preset pair: light as default, dark overrides when .dark is on.
Stage clips the slash. Track is the slanted band that travels.
Keep ease-in-out so the slash eases, not snaps.