PROGRESSIVE ENHANCEMENT LAYER MAP ================================== Layer 0 — This file renders in any browser, any era. Pure HTML. Layer 1 — @layer base : reset, tokens, readable defaults Layer 2 — @layer type : typographic scale, spacing rhythm Layer 3 — @layer layout : grid, flex, structure Layer 4 — @layer enhanced: custom properties, modern selectors Layer 5 — @layer motion : animation (prefers-reduced-motion gated) Layer 6 —