/* adia:primitive/elevation — Shadow primitives (L1).
   Material-style soft, diffused 4-layer shadows: ambient + penumbra +
   umbra + contact edge. Hue-tinted via neutral hue. --a-shadow-intensity
   lets themes control shadow strength (0 = flat, 2 = heavy).
   Moved verbatim out of tokens.css (v0.6.48 foundation reorg, ADR-0035). */

:root {
  --a-shadow-intensity: 1;
  --a-shadow-color: oklch(0.2 0.01 var(--a-neutral-hue));
  /* Per-layer alpha is applied via the oklch(from …) relative-color
     syntax — the legacy `var(--c) / alpha` form is invalid outside a
     color function and silently resolved to `box-shadow: none` (latent
     bug fixed 2026-04-27). */
  --a-shadow-sm:
    0 0.5px 0.5px  oklch(from var(--a-shadow-color) l c h / calc(0.04 * var(--a-shadow-intensity))),
    0 0.5px 1.5px  oklch(from var(--a-shadow-color) l c h / calc(0.03 * var(--a-shadow-intensity))),
    0 2px 4px  oklch(from var(--a-shadow-color) l c h / calc(0.02 * var(--a-shadow-intensity))),
    0 0   1px  oklch(from var(--a-shadow-color) l c h / calc(0.03 * var(--a-shadow-intensity)));
  --a-shadow-md:
    0 0.5px 1px  oklch(from var(--a-shadow-color) l c h / calc(0.04 * var(--a-shadow-intensity))),
    0 1.5px 3px  oklch(from var(--a-shadow-color) l c h / calc(0.03 * var(--a-shadow-intensity))),
    0 4px 12px oklch(from var(--a-shadow-color) l c h / calc(0.03 * var(--a-shadow-intensity))),
    0 0   1px  oklch(from var(--a-shadow-color) l c h / calc(0.04 * var(--a-shadow-intensity)));
  --a-shadow-lg:
    0 2px 4px  oklch(from var(--a-shadow-color) l c h / calc(0.03 * var(--a-shadow-intensity))),
    0 4px 8px  oklch(from var(--a-shadow-color) l c h / calc(0.03 * var(--a-shadow-intensity))),
    0 8px 24px oklch(from var(--a-shadow-color) l c h / calc(0.04 * var(--a-shadow-intensity))),
    0 0   1px  oklch(from var(--a-shadow-color) l c h / calc(0.04 * var(--a-shadow-intensity)));
}
