.exp-bar {
  display: flex;
  justify-content: space-between;
  gap: var(--space-medium);
  padding: var(--space-medium) var(--space-large);
  border-bottom: var(--border-width) solid var(--color-border);
  font-family: var(--font-mono);
  font-size: var(--size-xs);
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
}

.exp-bar a {
  color: inherit;
  text-decoration: none;
}

.opening {
  padding: var(--space-display) var(--space-large) var(--space-section);
  max-width: 46rem;
}

.kicker {
  font-family: var(--font-mono);
  font-size: var(--size-xs);
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-medium);
}

h1 {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 6vw, var(--size-3xl));
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  font-weight: var(--weight-medium);
  margin: 0 0 var(--space-medium);
}

.deck {
  color: var(--color-text-muted);
  max-width: var(--measure);
  margin: 0;
}

.story {
  display: grid;
  grid-template-columns: minmax(0, 28rem) minmax(18rem, 1fr);
  gap: var(--space-display);
  padding: 0 var(--space-large) var(--space-display);
  align-items: start;
}

.chapters section {
  min-height: 70vh;
  padding-top: var(--space-section);
}

.chapters h2 {
  font-family: var(--font-display);
  font-size: var(--size-xl);
  font-weight: var(--weight-medium);
  margin: 0 0 var(--space-medium);
}

.chapters p {
  margin: 0;
  max-width: var(--measure);
}

.stage {
  position: sticky;
  top: 4rem;
  align-self: start;
}

.stage svg {
  width: min(100%, 22rem);
  height: auto;
  display: block;
}

.stage circle {
  fill: var(--color-bg-elevated);
  stroke: var(--color-text);
  stroke-width: 1.4;
}

.stage text {
  font-family: var(--font-mono);
  font-size: 12px;
  text-anchor: middle;
  fill: var(--color-text);
}

.stage .name {
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  fill: var(--color-text-muted);
}

.stage line {
  stroke: var(--color-text);
  stroke-width: 1.4;
}

.part {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity var(--duration-slow) var(--ease-out),
    transform var(--duration-slow) var(--ease-out);
}

.stage[data-active="1"] .part-a,
.stage[data-active="2"] .part-a,
.stage[data-active="2"] .part-b,
.stage[data-active="2"] .part-ab,
.stage[data-active="3"] .part-a,
.stage[data-active="3"] .part-b,
.stage[data-active="3"] .part-c,
.stage[data-active="3"] .part-ab,
.stage[data-active="3"] .part-bc,
.stage[data-active="4"] .part {
  opacity: 1;
  transform: none;
}

.stage-caption {
  font-family: var(--font-mono);
  font-size: var(--size-xs);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-top: var(--space-medium);
}

@media (max-width: 800px) {
  .story {
    grid-template-columns: 1fr;
  }

  .stage {
    position: relative;
    top: 0;
    order: -1;
  }

  .chapters section {
    min-height: 0;
    padding-top: var(--space-large);
  }
}

@media (prefers-reduced-motion: reduce) {
  .part {
    transition: none;
    transform: none;
  }
}