/* =====================================================
 * D2. STAGGERED FADE-IN — toggleable add-on
 * Applied to card grid containers across the site.
 * -----------------------------------------------------
 * Triggers when grid scrolls into view (IntersectionObserver).
 * Each child card fades in with progressive delay (0.1s steps).
 *
 * To DISABLE: remove the 2 references from each HTML file:
 *   <link rel="stylesheet" href="assets/css/effect-stagger.css">
 *   <script src="assets/js/effect-stagger.js" defer></script>
 * ===================================================== */

.wanted-grid > *,
.service-grid > *,
.recommend-grid > *,
.cores-grid > *,
.as-grid > *,
.cases-grid > * {
  opacity: 0;
  transform: translateY(36px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
  will-change: opacity, transform;
}

.is-staggered > * {
  opacity: 1 !important;
  transform: translateY(0) !important;
}

.is-staggered > *:nth-child(1) { transition-delay: 0.05s; }
.is-staggered > *:nth-child(2) { transition-delay: 0.15s; }
.is-staggered > *:nth-child(3) { transition-delay: 0.25s; }
.is-staggered > *:nth-child(4) { transition-delay: 0.35s; }
.is-staggered > *:nth-child(5) { transition-delay: 0.45s; }
.is-staggered > *:nth-child(6) { transition-delay: 0.55s; }
.is-staggered > *:nth-child(7) { transition-delay: 0.65s; }
.is-staggered > *:nth-child(8) { transition-delay: 0.75s; }

@media (prefers-reduced-motion: reduce) {
  .wanted-grid > *, .service-grid > *, .recommend-grid > *,
  .cores-grid > *, .as-grid > *, .cases-grid > * {
    opacity: 1; transform: none; transition: none;
  }
}