Living topographic map: marching-squares contour lines over an evolving 3D value-noise terrain, thin minor strokes with a bold accent index line every fifth level, over soft posterized elevation bands. Cool cartographic default. Canvas 2D, seeded, offscreen-paused, DPR-clamped, reduced-motion-safe.
pnpm dlx shadcn@latest add "https://crucibleui.com/r/contour.json"