:root {
  /* Atmospheric cushioning — large spread, low opacity. No hard shadows. */
  --shadow-0: none;
  --shadow-1: rgba(0, 0, 0, 0.04) 0px 4px 24px 0px;   /* floating nav pill */
  --shadow-2: rgba(0, 0, 0, 0.08) 0px 24px 48px 0px;  /* hero / elevated cards */
  --shadow-3: rgba(0, 0, 0, 0.25) 0px 70px 110px 0px; /* rare dramatic tile */
}