:root {
  /* ── Radii — DS4 ladder: 36 shell/feature · 32 card · 20 dense · 14 tile · 999 pill ── */
  --radius-card:    32px;   /* cards, panels, modules */
  --radius-feature: 36px;   /* shells + hero / feature cards */
  --radius-dense:   20px;   /* dense-grid cards */
  --radius-tile:    14px;   /* nested tiles */
  --radius-pill:    999px;  /* pills, controls, inputs */
  --radius-box:     14px;   /* inner prompt box → nested tile */

  /* ── Motion ── */
  --spring: 280ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* ── Shadows — alias the DS4 neumorphic set (defined in colors.css) so the
        old --shadow-* names resolve to soft-3D lifts, not flat drop shadows. ── */
  --shadow-card:   var(--sh-card);
  --shadow-box:    var(--sh-control);
  --shadow-pill:   var(--sh-control);
  --shadow-search: var(--sh-inset);
  --shadow-folder: var(--sh-feature);
  --shadow-cursor: var(--sh-control);

  /* ── Layout ─────────────────────────────────────────────────────── */
  --container-max: 1100px;
  --column-reading: 752px;  /* the one centred column a full-screen conversation reads in */
  --fade-edge: var(--space-8);  /* how far a box that scrolls across fades at an edge with more beyond it */
  --grid-gap:      24px;
  --card-height:   340px;
  --card-pad:      24px;

  /* ── Page rhythm ────────────────────────────────────────────────── */
  --page-pad-y: 80px;
  --page-pad-x: 20px;

  /* ── Spacing scale (4px base) ───────────────────────────────────── */
  /* Shared rhythm for gaps/padding; adopt in touched files, not a sweep. */
  --space-1:  4px;
  --space-2:  8px;
  --space-3:  12px;
  --space-4:  16px;
  --space-5:  20px;
  --space-6:  24px;
  --space-8:  32px;
  --space-10: 40px;
}