/* Lumen — Borders, focus, elevation, motion */
:root {
  /* Borders & focus */
  --border-hairline: 1px solid var(--color-hairline);
  --rim-inset: inset 0 0 0 1px var(--alpha-hairline);
  --rim-inset-strong: inset 0 0 0 1px var(--alpha-hairline-strong);
  --focus-ring: 0 0 0 1px var(--color-lumen), 0 0 16px rgba(207, 216, 230, 0.25);

  /* Elevation — soft, very dark drop shadows only */
  --shadow-none: none;
  --shadow-card: 0 1px 1px rgba(0, 0, 0, 0.4),
                 0 12px 32px -12px rgba(0, 0, 0, 0.6);
  --shadow-raised: 0 2px 4px rgba(0, 0, 0, 0.5),
                   0 24px 48px -16px rgba(0, 0, 0, 0.7);

  /* Motion — a single signature easing */
  --motion-slow: 1s cubic-bezier(0.15, 0.83, 0.66, 1);   /* @kind other */
  --motion-medium: 420ms cubic-bezier(0.15, 0.83, 0.66, 1); /* @kind other */
  --motion-fast: 200ms cubic-bezier(0.15, 0.83, 0.66, 1); /* @kind other */
}