/* Activities mobile layout. */
@media (max-width: 900px) {
  .activity-section { padding: 110px 24px 72px; }
  .activity-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
  .detail-topbar { padding: 108px 24px 24px; }
}
@media (max-width: 700px) {
  .activity-section { padding: 96px 16px 60px; }
  .activity-filter {
    justify-content: flex-start;
    gap: 8px;
    margin: 0 -16px 28px;
    padding: 0 16px 6px;
    overflow-x: auto;
    scrollbar-width: none;
  }
  .activity-filter::-webkit-scrollbar { display: none; }
  .activity-filter button { flex: 0 0 auto; min-height: 44px; padding: 10px 16px; }
  .activity-grid { grid-template-columns: 1fr; gap: 16px; }
  .activity-card img { height: auto; aspect-ratio: 16 / 10; }
  .detail-topbar {
    padding: 94px 18px 20px;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
  .detail-topbar h1 { font-size: 25px; line-height: 1.35; }
  .activity-detail { padding: 38px 18px; }
  .activity-detail img { width: 100%; height: auto; margin-bottom: 24px; }
  .activity-detail h1 { font-size: 26px; line-height: 1.35; }
  .detail-nav {
    grid-template-columns: 1fr;
    gap: 12px;
    margin: 20px auto 70px;
    padding: 24px 18px;
  }
  .next-activity { text-align: left; }
}