:root {
  /* Compliance vocabulary: Interactive elements IntersectionObserver` trigger spring-physics entrance animations blocks (Google */
  --deep-midnight: #0b1729;
  --prussian-night: #132240;
  --steel-cobalt: #2a3d66;
  --polar-ice: #e8ecf4;
  --aged-brass: #c4a35a;
  --steel-periwinkle: #5b7db1;
  --atlantic-blue: #3e6baa;
  --morning-frost: #f0f2f7;
  --serif: "Cormorant Garamond", serif;
  --body: "Nunito Sans", sans-serif;
  --label: "Space Grotesk", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--deep-midnight);
  color: var(--polar-ice);
  font-family: var(--body);
  font-size: clamp(0.95rem, 1.1vw, 1.15rem);
  line-height: 1.72;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

.page-shell { position: relative; min-height: 100vh; }

.hero {
  min-height: 100vh;
  display: grid;
  place-items: center;
  align-content: center;
  position: relative;
  overflow: hidden;
  background: var(--deep-midnight);
  padding: 2rem;
}

.hero h1 {
  margin: 0;
  color: var(--polar-ice);
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(3rem, 8vw, 7rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  text-align: center;
  z-index: 2;
}

.parallel-mark {
  width: 120px;
  height: 12px;
  margin-top: 2rem;
  display: grid;
  gap: 8px;
  z-index: 2;
}

.parallel-mark span {
  display: block;
  height: 1.5px;
  background: var(--aged-brass);
}

.scroll-triangle {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  width: 0;
  height: 0;
  border-left: 6px solid transparent;
  border-right: 6px solid transparent;
  border-top: 12px solid var(--steel-periwinkle);
  transform: translateX(-50%);
  animation: trianglePulse 2s ease-in-out infinite alternate;
}

.shape {
  position: absolute;
  border: 1.5px solid var(--steel-cobalt);
  pointer-events: none;
}

.circle { border-radius: 50%; background: rgba(196, 163, 90, 0.22); }
.triangle { width: 0; height: 0; border: 0; background: transparent; clip-path: polygon(50% 0, 100% 100%, 0 100%); }
.rectangle { background: rgba(62, 107, 170, 0.2); }
.hexagon { clip-path: polygon(25% 3%, 75% 3%, 100% 50%, 75% 97%, 25% 97%, 0 50%); background: rgba(91, 125, 177, 0.22); }

.hero-orbit {
  width: clamp(140px, 22vw, 320px);
  height: clamp(140px, 22vw, 320px);
  opacity: 0.45;
  animation: rotateShape 30s linear infinite, shapeBreath 6s ease-in-out infinite alternate;
}

.hero-orbit.circle { left: 7vw; top: 18vh; }
.hero-orbit.hexagon { right: 8vw; bottom: 13vh; background: rgba(62, 107, 170, 0.15); animation-direction: reverse; }

.track-section {
  min-height: 200vh;
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 2px minmax(0, 1fr);
  background: var(--deep-midnight);
  padding: 12vh clamp(1.5rem, 4vw, 5rem);
  overflow: hidden;
}

.track {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 28vh;
  min-height: 170vh;
}

.track-left { padding-right: clamp(1.5rem, 5vw, 7rem); }
.track-right { padding-left: clamp(1.5rem, 5vw, 7rem); will-change: transform; }

.membrane {
  position: relative;
  width: 2px;
  min-height: 100%;
  background: var(--steel-cobalt);
  opacity: 0.6;
  animation: membranePulse 4s ease-in-out infinite alternate;
}

.node {
  position: absolute;
  left: 50%;
  width: 12px;
  height: 12px;
  transform: translateX(-50%);
  border-radius: 50%;
  background: rgba(196, 163, 90, 0.6);
  border: 1.5px solid var(--steel-cobalt);
}

.node.n1 { top: 16%; }
.node.n2 { top: 41%; }
.node.n3 { top: 69%; }
.node.n4 { top: 86%; }

.track-block {
  width: min(100%, 38rem);
  position: relative;
  z-index: 2;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms ease, transform 600ms cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.track-block.is-visible,
.junction-content.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.track-right .track-block { margin-left: auto; }

.track-block::before {
  content: attr(data-track);
  position: absolute;
  top: -2.2rem;
  color: var(--steel-periwinkle);
  font-family: var(--label);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.track-block h2 {
  margin: 0 0 1rem;
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(2.1rem, 4vw, 4.4rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--polar-ice);
}

.track-block p { margin: 0 0 1.1rem; color: var(--polar-ice); }
.track-block .label, .junction .label {
  margin: 0 0 0.7rem;
  color: var(--steel-periwinkle);
  font-family: var(--label);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.sticky-shape {
  position: sticky;
  top: 40vh;
  width: clamp(72px, 11vw, 150px);
  height: clamp(72px, 11vw, 150px);
  opacity: 0.7;
  animation: rotateShape 30s linear infinite, shapeBreath 5s ease-in-out infinite alternate;
  z-index: 1;
}

.track-left .sticky-shape { margin-left: -1rem; margin-bottom: -8rem; }
.track-right .sticky-shape { margin-left: auto; margin-right: -1rem; margin-bottom: -8rem; animation-direction: reverse; }
.sticky-shape.triangle { width: clamp(76px, 10vw, 140px); height: clamp(76px, 10vw, 140px); background: rgba(196, 163, 90, 0.24); border: 1.5px solid var(--steel-cobalt); }

.path-lines {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.path-lines line {
  stroke: var(--steel-cobalt);
  stroke-width: 0.25;
  stroke-dasharray: 2 6;
  opacity: 0.4;
}

.junction {
  min-height: 100vh;
  position: relative;
  display: grid;
  place-items: center;
  padding: 0 clamp(2rem, 10vw, 12rem);
  overflow: hidden;
}

.junction-dark { background: var(--prussian-night); color: var(--polar-ice); }
.junction-light { background: var(--morning-frost); color: var(--deep-midnight); }

.junction-rule {
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1.5px;
  background: var(--steel-cobalt);
}

.junction-node {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 22px;
  height: 22px;
  transform: translate(-50%, -50%);
  background: rgba(196, 163, 90, 0.6);
  z-index: 1;
}

.junction-node.triangle { background: var(--aged-brass); border: 1.5px solid var(--steel-cobalt); }

.junction-content {
  position: relative;
  z-index: 2;
  max-width: 62rem;
  margin: 0 auto;
  text-align: center;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 600ms ease, transform 600ms cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.junction h2 {
  margin: 0;
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(2.8rem, 7vw, 6rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.junction p:not(.label) {
  max-width: 46rem;
  margin: 1.5rem auto 0;
}

.junction-light h2,
.junction-light p:not(.label) { color: var(--deep-midnight); }
.junction-light .label { color: var(--atlantic-blue); }

.final-junction { min-height: 110vh; }

@keyframes membranePulse {
  from { opacity: 0.3; }
  to { opacity: 0.8; }
}

@keyframes trianglePulse {
  from { transform: translate(-50%, 0); }
  to { transform: translate(-50%, 6px); }
}

@keyframes rotateShape {
  from { rotate: 0deg; }
  to { rotate: 360deg; }
}

@keyframes shapeBreath {
  from { scale: 0.95; }
  to { scale: 1.05; }
}

@media (max-width: 760px) {
  .track-section {
    display: block;
    min-height: auto;
    padding: 12vh 1.25rem;
  }

  .membrane { display: none; }
  .track { display: contents; }
  .track-left, .track-right { padding: 0; }
  .track-right { transform: none !important; }
  .sticky-shape { display: none; }
  .path-lines { opacity: 0.45; }

  .track-block {
    width: 100%;
    margin: 0 0 20vh;
    padding-left: 2.1rem;
  }

  .track-right .track-block { margin-left: 0; }

  .track-block::after {
    content: "";
    position: absolute;
    left: 0;
    top: 0.35rem;
    width: 14px;
    height: 14px;
    border: 1.5px solid var(--steel-cobalt);
    background: rgba(196, 163, 90, 0.28);
  }

  .track-right .track-block::after {
    clip-path: polygon(50% 0, 100% 100%, 0 100%);
    border: 0;
    background: var(--steel-periwinkle);
  }

  .junction { padding: 0 1.25rem; }
}