:root {
  /* KF barely uses shadow. Elevation is expressed as a colour step
     (page -> white card -> black panel), with shadow reserved for
     floating chrome only. */
  --shadow-none: none;
  --shadow-nav: 0 2px 18px rgba(18, 18, 26, .10);
  --shadow-control: 0 1px 2px rgba(18, 18, 26, .08);
  --shadow-panel: 0 18px 48px rgba(18, 18, 26, .10);

  --hairline: 1px solid var(--border-hairline);
  --hairline-inverse: 1px solid var(--border-inverse);
}