/* ============================================================
   SXTN OS · Spacing & sizing tokens
   A tight 4px-based rhythm. The control surface is dense:
   panels breathe on 14–18px, grids gap on 10–14px.
   ============================================================ */
:root {
  /* ---- Spacing scale (4px base) ---- */
  --space-0: 0;
  --space-1: 2px;
  --space-2: 4px;
  --space-3: 7px;    /* chip / pill inner gap        */
  --space-4: 9px;    /* default inline gap           */
  --space-5: 12px;
  --space-6: 14px;   /* grid gap · card padding-y    */
  --space-7: 16px;   /* card padding-x               */
  --space-8: 18px;   /* panel padding                */
  --space-9: 22px;
  --space-10: 26px;  /* section gap                  */
  --space-12: 32px;
  --space-16: 48px;  /* page bottom padding          */

  /* ---- Layout rails (the SXTN OS shell) ---- */
  --rail-icon:   62px;    /* activity rail            */
  --rail-side:   218px;   /* contextual sidebar       */
  --topbar-h:    50px;    /* header                   */
  --content-max: 1280px;  /* main column cap          */

  /* ---- Component sizing ---- */
  --control-h:   30px;    /* buttons, chips           */
  --hit-min:     44px;    /* min touch target         */
  --led-sm:      7px;
  --led-md:      9px;
  --led-lg:      12px;
}