.build-sequence {
  position: relative;
  z-index: 4;                                /* over Film Reel + Configurator + Hero */
  background: var(--bg-primary);
  color: var(--ivory);
  height: 300vh;
  border-top: 1px solid var(--gold-faint);
}

.build-sequence__pin {
  position: relative;
  height: 100vh;
  width: 100%;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.build-sequence__head {
  max-width: var(--max-w);
  margin: 0 auto;
  width: 100%;
  padding: clamp(48px, 6vw, 96px) var(--gutter) 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.build-sequence__label {
  font-family: var(--font-body);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold-mid);
}

.build-sequence__title {
  font-family: var(--font-display);
  font-size: clamp(28px, 4.6vw, 60px);
  line-height: 1.1;
  font-weight: 400;
  color: var(--ivory);
}

.build-sequence__title em {
  font-style: italic;
  background: var(--gold-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.build-sequence__sub {
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--ivory-dim);
  max-width: 640px;
}

.build-sequence__animation {
  flex: 1 1 auto;
  position: relative;
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 0;
  max-width: var(--max-w);
  margin: 0 auto;
  width: 100%;
  padding: 0 var(--gutter);
  align-items: stretch;
  min-height: 0;
}

.build-sequence__stage {
  position: relative;
  border: 1px solid var(--gold-faint);
  background: var(--bg-hero);
  overflow: hidden;
  min-height: 320px;
  aspect-ratio: 16 / 10;
}

/* Phase images stacked, opacity-toggled by scroll progress */
.build-sequence__phase {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 600ms var(--ease-cinema);
  filter: brightness(0.92) saturate(0.98);
  will-change: opacity;
}
.build-sequence__phase.is-active { opacity: 1; }

/* Subtle vignette on top so the active phase reads cinematic */
.build-sequence__stage::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(13,13,13,0.10) 0%, rgba(13,13,13,0) 30%, rgba(13,13,13,0) 70%, rgba(13,13,13,0.55) 100%);
  pointer-events: none;
  z-index: 1;
}

.build-sequence__progress {
  position: absolute;
  left: 0; bottom: 0;
  height: 2px;
  width: 0%;
  background: linear-gradient(90deg, var(--gold-dark), var(--gold-primary));
  z-index: 3;
  transition: width 80ms linear;
}

.build-sequence__labels {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 18px;
  padding-left: 28px;
  border-left: 1px solid var(--gold-faint);
  margin-left: 24px;
}

.build-sequence__label-row {
  display: flex;
  align-items: baseline;
  gap: 14px;
  opacity: 0.32;
  transition: opacity 320ms var(--ease-soft), color 320ms var(--ease-soft);
}

.build-sequence__label-row.is-active {
  opacity: 1;
}

.build-sequence__label-num {
  font-family: var(--font-body);
  font-size: 10px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold-mid);
  width: 28px;
}

.build-sequence__label-name {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 18px;
  color: var(--ivory);
}

.build-sequence__label-row.is-active .build-sequence__label-name { color: var(--gold-primary); }

/* PLOT COLLAB BLOCK */

.plot-collab {
  position: relative;
  z-index: 5;
  background: var(--bg-warm);
  padding: clamp(96px, 11vw, 160px) 0 clamp(96px, 11vw, 160px);
  border-top: 1px solid var(--gold-faint);
}

.plot-collab__inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: clamp(30px, 4vw, 60px);
}

.plot-collab__heading {
  font-family: var(--font-body);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold-mid);
}

.plot-collab__cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(20px, 3vw, 40px);
  width: 100%;
  max-width: 1100px;
}

.plot-card {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 28px 24px;
  border: 1px solid var(--gold-faint);
  background: rgba(13,13,13,0.4);
  text-align: left;
  transition: border-color 320ms var(--ease-soft), background 320ms var(--ease-soft);
}

.plot-card:hover { border-color: var(--gold-line); background: rgba(13,13,13,0.6); }

.plot-card__num {
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--gold-primary);
}

.plot-card__text {
  font-family: var(--font-display);
  font-size: clamp(18px, 2vw, 24px);
  line-height: 1.3;
  color: var(--ivory);
}

.plot-collab__ctas {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

.plot-collab__cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 28px;
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ivory);
  border: 1px solid var(--gold-line);
  background: rgba(13,13,13,0.35);
  transition: background 320ms var(--ease-soft), color 320ms var(--ease-soft), border-color 320ms var(--ease-soft);
}

/* Outline CTA hover — stays a ghost button; border + text brighten to gold */
.plot-collab__cta:hover {
  background: rgba(212, 175, 55, 0.08);
  color: var(--gold-primary);
  border-color: var(--gold-primary);
}

.plot-collab__cta--solid {
  background: var(--gold-primary);
  color: var(--bg-primary);
  border-color: var(--gold-primary);
}

/* Solid CTA hover — stays solid yellow; deepens to darker gold for a pressed feel */
.plot-collab__cta--solid:hover {
  background: var(--gold-dark);
  color: var(--bg-primary);
  border-color: var(--gold-dark);
}

@media (max-width: 880px) {
  .build-sequence { height: auto; }
  .build-sequence__pin { height: auto; }
  .build-sequence__animation {
    grid-template-columns: 1fr;
    gap: 24px;
    padding-bottom: 32px;
  }
  .build-sequence__labels {
    padding-left: 0;
    border-left: 0;
    margin-left: 0;
    flex-direction: row;
    overflow-x: auto;
    gap: 14px;
    padding-bottom: 8px;
  }
  .build-sequence__label-row { flex: 0 0 auto; }
  .plot-collab__cards { grid-template-columns: 1fr; }
  .plot-collab__cta { flex: 1 1 auto; justify-content: center; }
}