/* Derived display assets retain the approved artwork. No motion timing changes. */
@media (max-width:700px), (pointer:coarse) {
  /* Avoid a full-screen procedural SVG filter on phones. Same noise, baked once. */
  .paper-grain {
    background-image:url('../assets/DRAFT_paper-grain-mobile.webp');
    background-size:160px 160px;
    background-repeat:repeat;
  }
  /* Hidden chapters do not need permanent GPU layers. */
  .chapter { will-change:auto; }
}