/* ===========================================================
   Section 4 — Amenities
   "The Cascade" — one amenity group visible at a time (Sky &
   Water shown by default), switched via a pill filter bar.
   Each group's photos still cascade in a staggered staircase,
   text always left / images always right, crossfading between
   groups so the page never grows past one tier's height.
   =========================================================== */

.sec4 {
  position: relative;
  background: var(--onyx);
  padding: clamp(40px, 5vw, 70px) 0 clamp(35px, 4.5vw, 60px);
  overflow: hidden;
}

.sec4::before {
  content: "";
  position: absolute;
  top: -18%;
  right: -14%;
  width: min(58vw, 860px);
  height: min(58vw, 860px);
  background: radial-gradient(
    circle,
    color-mix(in srgb, var(--gold) 13%, transparent) 0%,
    transparent 68%
  );
  pointer-events: none;
}

.sec4__inner {
  position: relative;
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 clamp(28px, 6vw, 88px);
}

/* ---------------------------------------------------------
   Eyebrow + heading — same rhythm as sections 2 & 3
   --------------------------------------------------------- */
.sec4__eyebrow {
  display: flex;
  align-items: center;
  gap: clamp(14px, 1.6vw, 20px);
  margin: 0 0 clamp(26px, 3.4vw, 40px);

  opacity: 0;
  transform: translateY(16px);
  transition:
    opacity 0.9s var(--ease-luxe),
    transform 0.9s var(--ease-luxe);
}

.sec4__eyebrow-index {
  font-family: var(--font-body);
  font-style: italic;
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.sec4__eyebrow-rule {
  width: 48px;
  height: 1px;
  background: color-mix(in srgb, var(--gold) 45%, transparent);
}

.sec4__eyebrow-label {
  font-family: var(--font-body);
  font-style: italic;
  font-size: 0.82rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ivory-dim);
}

.sec4__head {
  max-width: 900px;
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 1.1s var(--ease-luxe) 0.1s,
    transform 1.1s var(--ease-luxe) 0.1s;
}

.sec4__heading {
  font-family: var(--font-display);
  font-weight: 700;
  text-transform: uppercase;
  color: var(--ivory);
  font-size: clamp(2rem, 4.6vw, 3.6rem);
  line-height: 1.16;
  letter-spacing: 0.015em;
  margin: 0 0 clamp(18px, 2vw, 26px);
}

.sec4__subhead {
  font-family: var(--font-body);
  font-weight: 400;
  color: var(--ivory-dim);
  font-size: clamp(1rem, 1.25vw, 1.18rem);
  line-height: 1.75;
  margin: 0;
}

.sec4.is-inview .sec4__eyebrow,
.sec4.is-inview .sec4__head {
  opacity: 1;
  transform: none;
}

/* ---------------------------------------------------------
   Group filter bar — pill chips, "Sky & Water" active by
   default. Reused verbatim as the section's only navigation;
   there is no "All" option, exactly one group is shown.
   --------------------------------------------------------- */
.sec4__filters {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(10px, 1.2vw, 14px);
  margin-top: clamp(40px, 5vw, 56px);

  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 1s var(--ease-luxe) 0.2s,
    transform 1s var(--ease-luxe) 0.2s;
}

.sec4.is-inview .sec4__filters {
  opacity: 1;
  transform: none;
}

.sec4__filter {
  background: transparent;
  border: 1px solid color-mix(in srgb, var(--ivory) 22%, transparent);
  color: var(--ivory-dim);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 11px 20px;
  border-radius: 999px;
  transition:
    color 0.35s var(--ease-luxe),
    border-color 0.35s var(--ease-luxe),
    background 0.35s var(--ease-luxe);
}

.sec4__filter:hover {
  color: var(--ivory);
  border-color: color-mix(in srgb, var(--gold) 55%, transparent);
}

.sec4__filter.is-active {
  color: var(--onyx);
  background: var(--gold);
  border-color: var(--gold);
}

/* ---------------------------------------------------------
   The Cascade — one active tier, crossfaded on group switch
   --------------------------------------------------------- */
.sec4__stage {
  position: relative;
  margin-top: clamp(48px, 6vw, 76px);
}

.sec4__tier {
  display: none;
  grid-template-columns: minmax(240px, 0.85fr) minmax(400px, 1.45fr);
  column-gap: clamp(8px, 1vw, 16px);
  row-gap: clamp(14px, 1.5vw, 20px);
  align-items: start;

  opacity: 0;
  transform: translateY(16px);
  transition:
    opacity 0.5s var(--ease-luxe),
    transform 0.5s var(--ease-luxe);
}

.sec4__tier.is-prep {
  display: grid;
}

.sec4__tier.is-active {
  display: grid;
  opacity: 1;
  transform: none;
}

.sec4__tier.is-out {
  display: grid;
  opacity: 0;
  transform: translateY(-10px);
  transition-duration: 0.35s;
}

/* ---- text column ---- */
.sec4__tier-text {
  padding-top: 2px;
}

.sec4__tier-label {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  text-transform: uppercase;
  color: var(--ivory);
  font-size: clamp(1.4rem, 2.2vw, 2rem);
  letter-spacing: 0.02em;
  margin: 0 0 clamp(14px, 1.6vw, 20px);
}

.sec4__tier-desc {
  font-family: var(--font-body);
  font-weight: 400;
  color: var(--ivory-dim);
  font-size: clamp(0.96rem, 1.1vw, 1.08rem);
  line-height: 1.75;
  max-width: 42ch;
  margin: 0 0 clamp(18px, 2vw, 26px);
}

.sec4__tier-list {
  font-family: var(--font-body);
  font-style: italic;
  color: var(--gold-soft);
  font-size: 0.86rem;
  letter-spacing: 0.02em;
  line-height: 1.7;
  max-width: 40ch;
  margin: 0;
  padding-top: clamp(16px, 1.8vw, 22px);
  border-top: 1px solid color-mix(in srgb, var(--ivory) 14%, transparent);
}

/* ---- image cluster — the staircase ---- */
.sec4__cluster {
  display: flex;
  align-items: flex-start;
  flex-wrap: nowrap;
}

.sec4__cluster-item {
  position: relative;
  flex: none;
  aspect-ratio: 1 / 1;
  width: clamp(168px, 16.2vw, 256px);
  margin: 0;
  border: 1px solid color-mix(in srgb, var(--gold) 30%, transparent);
  background: var(--onyx-soft);
  box-shadow: 0 20px 44px color-mix(in srgb, var(--onyx) 60%, transparent);
  overflow: hidden;

  opacity: 0;
  transform: translateY(30px) scale(0.94);
  transition:
    opacity 0.7s var(--ease-luxe),
    transform 0.7s var(--ease-luxe),
    box-shadow 0.4s var(--ease-luxe);
}

.sec4.is-inview .sec4__tier.is-active .sec4__cluster-item {
  opacity: 1;
  transform: none;
}

.sec4__tier.is-out .sec4__cluster-item {
  opacity: 0 !important;
  transform: translateY(-8px) scale(0.96) !important;
  transition-delay: 0s !important;
  transition-duration: 0.3s !important;
}

.sec4__cluster-item:hover {
  z-index: 6;
  box-shadow: 0 26px 54px color-mix(in srgb, var(--onyx) 72%, transparent);
}

.sec4__cluster-item img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 1.1s var(--ease-luxe);
}

.sec4__cluster-item:hover img {
  transform: scale(1.08);
}

/* step sizing + vertical/horizontal cascade offsets */
.sec4__cluster-item:nth-child(1) {
  width: clamp(192px, 18.4vw, 288px);
  z-index: 5;
  transition-delay: 0.04s;
}
.sec4__cluster-item:nth-child(2) {
  width: clamp(156px, 14.8vw, 230px);
  margin-top: clamp(39px, 4.4vw, 60px);
  margin-left: clamp(-28px, -2.3vw, -18px);
  z-index: 4;
  transition-delay: 0.16s;
}
.sec4__cluster-item:nth-child(3) {
  width: clamp(130px, 12.5vw, 194px);
  margin-top: clamp(78px, 8.8vw, 120px);
  margin-left: clamp(-28px, -2.3vw, -18px);
  z-index: 3;
  transition-delay: 0.28s;
}
.sec4__cluster-item:nth-child(4) {
  width: clamp(112px, 10.7vw, 166px);
  margin-top: clamp(117px, 13.3vw, 180px);
  margin-left: clamp(-26px, -2.1vw, -16px);
  z-index: 2;
  transition-delay: 0.4s;
}
.sec4__cluster-item:nth-child(5) {
  width: clamp(96px, 9.1vw, 142px);
  margin-top: clamp(156px, 17.7vw, 240px);
  margin-left: clamp(-23px, -1.8vw, -13px);
  z-index: 1;
  transition-delay: 0.52s;
}

/* ---------------------------------------------------------
   Tablet — stack text above cluster
   --------------------------------------------------------- */
@media (max-width: 900px) {
  .sec4__tier.is-active,
  .sec4__tier.is-prep,
  .sec4__tier.is-out {
    grid-template-columns: 1fr;
  }

  .sec4__filters {
    flex-wrap: nowrap;
    overflow-x: auto;
    padding-bottom: 4px;
    scrollbar-width: none;
  }

  .sec4__filters::-webkit-scrollbar {
    display: none;
  }

  .sec4__filter {
    flex-shrink: 0;
  }
}

@media (max-width: 640px) {
  .sec4 {
    padding: clamp(60px, 15vw, 90px) 0 clamp(54px, 13vw, 80px);
  }

  .sec4__heading {
    font-size: clamp(1.8rem, 8vw, 2.4rem);
  }

  .sec4__stage {
    margin-top: clamp(40px, 10vw, 56px);
  }

  .sec4__cluster-item:nth-child(1) {
    width: clamp(136px, 38vw, 190px);
  }
  .sec4__cluster-item:nth-child(2) {
    width: clamp(113px, 31vw, 154px);
    margin-top: clamp(28px, 9vw, 43px);
  }
  .sec4__cluster-item:nth-child(3) {
    width: clamp(96px, 26vw, 129px);
    margin-top: clamp(55px, 17vw, 85px);
  }
  .sec4__cluster-item:nth-child(4) {
    width: clamp(80px, 22vw, 111px);
    margin-top: clamp(83px, 26vw, 128px);
  }
  .sec4__cluster-item:nth-child(5) {
    width: clamp(70px, 19vw, 96px);
    margin-top: clamp(110px, 35vw, 170px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .sec4__tier,
  .sec4__cluster-item {
    transition-duration: 0.01ms !important;
    transition-delay: 0s !important;
  }

  .sec4__cluster-item img {
    transition: none !important;
  }
}