/* ==========================================================================
   Features — Premium 3D cards (GPU-only transforms)
   ========================================================================== */

/* Intro block above feature cards */
.features__intro {
  margin-bottom: clamp(2rem, 4vw, 3rem);
}

.hero.hero--premium + .features .features__intro {
  margin-top: 0;
}

.hero.hero--premium + .features .features__intro-inner {
  padding: var(--space-6) var(--space-5);
}

.features__intro-inner {
  max-width: 720px;
  margin-inline: auto;
  text-align: center;
  padding: var(--space-8) var(--space-6);
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, rgba(236, 253, 245, 0.55) 0%, rgba(255, 255, 255, 0.72) 50%, rgba(255, 251, 235, 0.45) 100%);
  border: 1px solid rgba(255, 255, 255, 0.7);
  -webkit-backdrop-filter: blur(16px) saturate(1.1);
  backdrop-filter: blur(16px) saturate(1.1);
  box-shadow: var(--shadow-sm), inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

body.page-landing .features__intro-inner {
  background: linear-gradient(135deg, rgba(236, 253, 245, 0.48) 0%, rgba(255, 255, 255, 0.65) 50%, rgba(255, 251, 235, 0.4) 100%);
}

.features__intro-title {
  margin: 0 0 var(--space-4);
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
  font-weight: 800;
  letter-spacing: var(--tracking-tight);
  color: var(--color-text);
  line-height: 1.3;
}

.features__intro-desc {
  margin: 0 0 var(--space-6);
  font-size: var(--text-base);
  line-height: 1.75;
  color: var(--color-text-secondary);
}

.features__intro-highlights {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3) var(--space-6);
  margin: 0;
  padding: 0;
  list-style: none;
}

.features__intro-highlights li {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-primary-dark);
}

.features__intro-highlights li span {
  color: var(--color-primary);
  font-size: 0.65em;
}

.features--premium .features__grid,
.courses--premium .courses__grid {
  perspective: 1200px;
}

/* Override legacy landing.css hover (JS-driven tilt only) */
.features--premium .feature-card--premium:hover,
.courses--premium .feature-card--premium:hover,
.features--premium .feature-card--premium:hover::before,
.courses--premium .feature-card--premium:hover::before {
  transform: perspective(1000px)
    rotateX(calc(var(--tilt-y) * -1deg))
    rotateY(calc(var(--tilt-x) * 1deg))
    translate3d(0, calc(var(--lift) * 1px), 0);
  opacity: 1;
  box-shadow: none;
  border-color: transparent;
}

.features--premium .feature-card--premium::before,
.courses--premium .feature-card--premium::before {
  display: none;
}

.feature-card--premium {
  --tilt-x: 0;
  --tilt-y: 0;
  --lift: 0;
  --shine-x: 50%;
  --shine-y: 50%;
  --glow: 0;
  position: relative;
  padding: 0;
  border: none;
  background: transparent;
  box-shadow: none;
  transform-style: preserve-3d;
  transform: perspective(1000px)
    rotateX(calc(var(--tilt-y) * -1deg))
    rotateY(calc(var(--tilt-x) * 1deg))
    translate3d(0, calc(var(--lift) * 1px), 0);
  transition:
    transform 0.12s cubic-bezier(0.23, 1, 0.32, 1),
    box-shadow 0.18s ease;
  contain: layout style;
  content-visibility: auto;
  contain-intrinsic-size: auto 280px;
  will-change: transform;
}

.feature-card--premium:not(.is-hovered) {
  will-change: auto;
}

.feature-card--premium.is-hovered {
  --lift: -10;
  --glow: 1;
}

.feature-card--premium .feature-card__surface {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  min-height: 100%;
  padding: var(--space-6);
  border-radius: var(--radius-xl);
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(255, 255, 255, 0.75);
  -webkit-backdrop-filter: blur(18px) saturate(1.12);
  backdrop-filter: blur(18px) saturate(1.12);
  box-shadow:
    0 1px 2px rgba(15, 23, 42, 0.04),
    0 8px 24px rgba(15, 23, 42, 0.06),
    inset 0 1px 0 rgba(255, 255, 255, 0.85);
  overflow: hidden;
  transform: translateZ(0);
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

body.page-landing .feature-card--premium .feature-card__surface {
  background: rgba(255, 255, 255, 0.68);
}

.feature-card--premium.is-hovered .feature-card__surface {
  border-color: rgba(5, 150, 105, 0.35);
  box-shadow:
    0 4px 8px rgba(15, 23, 42, 0.04),
    0 20px 48px rgba(5, 150, 105, 0.14),
    0 0 0 1px rgba(16, 185, 129, 0.08);
}

.feature-card__shine {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  opacity: calc(var(--glow) * 0.85);
  background: radial-gradient(
    280px circle at var(--shine-x) var(--shine-y),
    rgba(255, 255, 255, 0.55) 0%,
    rgba(16, 185, 129, 0.12) 35%,
    transparent 65%
  );
  transition: opacity 0.15s ease;
  z-index: 2;
}

.feature-card__border-glow {
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(
    135deg,
    rgba(5, 150, 105, calc(var(--glow) * 0.6)),
    transparent 40%,
    rgba(251, 191, 36, calc(var(--glow) * 0.45))
  );
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: exclude;
  pointer-events: none;
  opacity: var(--glow);
  z-index: 3;
  transition: opacity 0.15s ease;
}

.feature-card__body {
  position: relative;
  z-index: 4;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  flex: 1;
  transform: translateZ(24px);
}

.feature-card--premium .feature-card__icon,
.feature-card--premium .ds-icon-tile {
  transform: translateZ(36px);
  transition:
    transform 0.2s cubic-bezier(0.23, 1, 0.32, 1),
    background 0.2s ease,
    color 0.2s ease,
    box-shadow 0.2s ease;
}

.feature-card--premium.is-hovered .feature-card__icon,
.feature-card--premium.is-hovered .ds-icon-tile {
  transform: translateZ(48px) scale(1.08) rotate(-4deg);
  background: var(--gradient-primary) !important;
  color: #fff !important;
  box-shadow: 0 8px 24px rgba(5, 150, 105, 0.35);
}

.feature-card--premium.is-hovered .feature-card__icon svg,
.feature-card--premium.is-hovered .ds-icon-tile svg {
  stroke: #fff;
}

.feature-card--premium .feature-card__title {
  transform: translateZ(20px);
  transition: color 0.15s ease;
}

.feature-card--premium.is-hovered .feature-card__title {
  color: var(--color-primary-dark);
}

.feature-card--premium .feature-card__desc {
  transform: translateZ(12px);
}

.feature-card--premium .feature-card__link {
  transform: translateZ(28px);
  margin-top: auto;
  padding-top: var(--space-2);
}

.feature-card--premium .feature-card__link svg {
  transition: transform 0.15s cubic-bezier(0.23, 1, 0.32, 1);
}

.feature-card--premium.is-hovered .feature-card__link svg {
  transform: translateX(5px);
}

/* Scroll reveal — no AOS delay */
.feature-card--premium {
  opacity: 0;
  transform: perspective(1000px) translate3d(0, 28px, 0) rotateX(0) rotateY(0);
}

.feature-card--premium.is-revealed {
  opacity: 1;
  transform: perspective(1000px)
    rotateX(calc(var(--tilt-y) * -1deg))
    rotateY(calc(var(--tilt-x) * 1deg))
    translate3d(0, calc(var(--lift) * 1px), 0);
  transition:
    opacity 0.5s cubic-bezier(0.23, 1, 0.32, 1),
    transform 0.12s cubic-bezier(0.23, 1, 0.32, 1),
    box-shadow 0.18s ease;
}

.features--premium .feature-card--premium:nth-child(1) { transition-delay: 0ms; }
.features--premium .feature-card--premium:nth-child(2) { transition-delay: 40ms; }
.features--premium .feature-card--premium:nth-child(3) { transition-delay: 80ms; }
.features--premium .feature-card--premium:nth-child(4) { transition-delay: 120ms; }
.features--premium .feature-card--premium:nth-child(5) { transition-delay: 160ms; }
.features--premium .feature-card--premium:nth-child(6) { transition-delay: 200ms; }
.features--premium .feature-card--premium:nth-child(7) { transition-delay: 240ms; }
.features--premium .feature-card--premium:nth-child(8) { transition-delay: 280ms; }

@media (prefers-reduced-motion: reduce) {
  .feature-card--premium,
  .feature-card--premium.is-revealed {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .feature-card--premium.is-hovered .feature-card__surface {
    box-shadow: var(--shadow-md);
  }
}

@media (max-width: 1023px) {
  .feature-card--premium,
  .feature-card--premium.is-revealed {
    transform: translate3d(0, 0, 0);
  }

  .feature-card--premium.is-hovered {
    --lift: -4;
  }
}