/* ── Reset & Base ─────────────────────────────────────── */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --font-display: 'Syne', sans-serif;
  --font-body: 'Libre Baskerville', serif;

  --bg-hero: #0c1220;
  --accent-hero: #c8a46e;
  --glow-hero: #c8a46e44;

  --bg-city: #1a1020;
  --accent-city: #f0a050;
  --glow-city: #f0a05044;

  --bg-mountains: #0a1a12;
  --accent-mountains: #4ecdc4;
  --glow-mountains: #4ecdc444;

  --bg-rocket: #120a1e;
  --accent-rocket: #7c5cfc;
  --glow-rocket: #7c5cfc44;

  --bg-circuit: #0a1518;
  --accent-circuit: #00d4aa;
  --glow-circuit: #00d4aa44;

  --bg-waves: #1a0a10;
  --accent-waves: #ff6b8a;
  --glow-waves: #ff6b8a44;

  --ease-out-cubic: cubic-bezier(0.33, 1, 0.68, 1);
  --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background: var(--bg-hero);
  color: #e8e4df;
  overflow-x: hidden;
  line-height: 1.6;
}

.app {
  position: relative;
}

/* ── Sections ────────────────────────────────────────── */
.scene {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.scene-inner {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 4rem;
  align-items: center;
  width: min(90%, 1280px);
  padding: 6rem 0;
}

/* ── Hero ─────────────────────────────────────────────── */
.scene--hero {
  flex-direction: column;
  justify-content: center;
}

.scene--hero .scene-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 2rem;
}

.hero-title {
  width: min(80%, 520px);
}

.hero-letters {
  width: 100%;
  height: auto;
  filter: drop-shadow(0 0 12px var(--glow-hero));
}

.hero-letter {
  stroke-dasharray: var(--len, 600);
  stroke-dashoffset: var(--len, 600);
  animation: heroDrawLetter 1.6s var(--ease-out-quart) forwards;
  animation-delay: calc(var(--i) * 0.25s);
}

@keyframes heroDrawLetter {
  to { stroke-dashoffset: 0; }
}

/* Fade-in elements after hero draw */
.hero-fade {
  opacity: 0;
  transform: translateY(12px);
  animation: heroFadeIn 0.8s var(--ease-out-cubic) forwards;
  animation-delay: 1.4s;
}

.scene-eyebrow.hero-fade {
  animation-delay: 1.1s;
}

@keyframes heroFadeIn {
  to { opacity: 1; transform: translateY(0); }
}

/* Scroll arrow */
.scroll-arrow {
  opacity: 0;
  animation: heroFadeIn 0.8s var(--ease-out-cubic) forwards;
  animation-delay: 1.8s;
}

.scroll-arrow svg {
  animation: arrowBob 2s ease-in-out infinite;
  animation-delay: 2.5s;
}

@keyframes arrowBob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(8px); }
}

.scene-eyebrow {
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  opacity: 0.5;
  margin-bottom: 1rem;
}

.hero-subtitle {
  font-family: var(--font-body);
  font-style: italic;
  font-size: clamp(1rem, 2vw, 1.25rem);
  opacity: 0.6;
  max-width: 28ch;
}

/* ── Parallax ────────────────────────────────────────── */
[data-speed] {
  will-change: transform;
}

/* ── Scene Text ──────────────────────────────────────── */
.scene-label {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(3rem, 6vw, 5rem);
  opacity: 0.08;
  line-height: 1;
  margin-bottom: -0.5rem;
}

.scene-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.8rem, 4vw, 3rem);
  line-height: 1.15;
  margin-bottom: 1rem;
}

.scene-desc {
  font-size: clamp(0.9rem, 1.2vw, 1.05rem);
  opacity: 0.65;
  max-width: 36ch;
  line-height: 1.7;
}

/* ── Scene SVG Container ─────────────────────────────── */
.scene-svg {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.scene-svg svg {
  width: 100%;
  height: auto;
  max-height: 60vh;
}

/* ── Section Colors ──────────────────────────────────── */
[data-scene="hero"] {
  background: var(--bg-hero);
  color: #e8e4df;
}

[data-scene="city"] {
  background: var(--bg-city);
  --scene-accent: var(--accent-city);
  --scene-glow: var(--glow-city);
}

[data-scene="mountains"] {
  background: var(--bg-mountains);
  --scene-accent: var(--accent-mountains);
  --scene-glow: var(--glow-mountains);
}

[data-scene="rocket"] {
  background: var(--bg-rocket);
  --scene-accent: var(--accent-rocket);
  --scene-glow: var(--glow-rocket);
}

[data-scene="circuit"] {
  background: var(--bg-circuit);
  --scene-accent: var(--accent-circuit);
  --scene-glow: var(--glow-circuit);
}

[data-scene="waves"] {
  background: var(--bg-waves);
  --scene-accent: var(--accent-waves);
  --scene-glow: var(--glow-waves);
}

/* Accent color on scene titles */
.scene:not(.scene--hero) .scene-title {
  color: var(--scene-accent);
}

.scene:not(.scene--hero) .scene-label {
  color: var(--scene-accent);
  opacity: 0.12;
}

/* SVG stroke color per section */
[data-scene="city"] .scene-svg svg { stroke: var(--accent-city); }
[data-scene="mountains"] .scene-svg svg { stroke: var(--accent-mountains); }
[data-scene="rocket"] .scene-svg svg { stroke: var(--accent-rocket); }
[data-scene="circuit"] .scene-svg svg { stroke: var(--accent-circuit); }
[data-scene="waves"] .scene-svg svg { stroke: var(--accent-waves); }

/* SVG glow effect */
.scene-svg svg {
  filter: drop-shadow(0 0 8px var(--scene-glow, transparent));
  transition: filter 0.6s ease, transform 0.6s var(--ease-out-cubic);
}

.scene-svg:hover svg {
  filter: drop-shadow(0 0 16px var(--scene-glow, transparent))
         drop-shadow(0 0 32px var(--scene-glow, transparent));
  transform: scale(1.02);
}

/* ── Gradient Transitions Between Sections ───────────── */
.scene::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 30vh;
  background: linear-gradient(to bottom, transparent, var(--next-bg, transparent));
  pointer-events: none;
  z-index: 1;
}

[data-scene="hero"]::after { --next-bg: var(--bg-city); }
[data-scene="city"]::after { --next-bg: var(--bg-mountains); }
[data-scene="mountains"]::after { --next-bg: var(--bg-rocket); }
[data-scene="rocket"]::after { --next-bg: var(--bg-circuit); }
[data-scene="circuit"]::after { --next-bg: var(--bg-waves); }
[data-scene="waves"]::after { display: none; }

/* ── Grain Overlay ───────────────────────────────────── */
.app::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 180px 180px;
}

/* ── Scene Inner z-index above gradient ──────────────── */
.scene-inner {
  position: relative;
  z-index: 2;
}

.scroll-arrow {
  z-index: 2;
}

/* ── Progress Indicator ──────────────────────────────── */
.progress-track {
  position: fixed;
  top: 0;
  right: 0;
  width: 3px;
  height: 100vh;
  z-index: 100;
  pointer-events: none;
}

.progress-fill {
  width: 100%;
  height: 0%;
  background: linear-gradient(
    to bottom,
    var(--accent-hero),
    var(--accent-city),
    var(--accent-mountains),
    var(--accent-rocket),
    var(--accent-circuit),
    var(--accent-waves)
  );
  box-shadow: 0 0 8px var(--accent-hero), 0 0 16px var(--accent-hero);
  transition: height 0.1s linear;
  border-radius: 0 0 2px 2px;
}

/* ── Navigation Dots ─────────────────────────────────── */
.nav-dots {
  position: fixed;
  right: 1.5rem;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
  z-index: 100;
}

.nav-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1.5px solid rgba(255, 255, 255, 0.35);
  background: transparent;
  cursor: pointer;
  transition: all 0.35s var(--ease-out-cubic);
  position: relative;
  padding: 0;
}

.nav-dot:hover {
  border-color: rgba(255, 255, 255, 0.8);
  transform: scale(1.3);
}

.nav-dot.active {
  background: #fff;
  border-color: #fff;
  transform: scale(1.2);
  box-shadow: 0 0 10px rgba(255, 255, 255, 0.4);
}

.nav-dot.active::after {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.2);
  animation: dotPulse 2s ease-in-out infinite;
}

@keyframes dotPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.6); opacity: 0; }
}

/* Tooltip */
.nav-tooltip {
  position: absolute;
  right: calc(100% + 12px);
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-display);
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  white-space: nowrap;
  color: rgba(255, 255, 255, 0.8);
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(6px);
  padding: 0.3em 0.6em;
  border-radius: 4px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  transform: translateY(-50%) translateX(4px);
}

.nav-dot:hover .nav-tooltip {
  opacity: 1;
  transform: translateY(-50%) translateX(0);
}

/* ── Responsive ──────────────────────────────────────── */
@media (max-width: 900px) {
  .scene-inner {
    grid-template-columns: 1fr;
    gap: 2.5rem;
    padding: 4rem 0;
  }

  .scene-text {
    text-align: center;
  }

  .scene-desc {
    max-width: 48ch;
    margin: 0 auto;
  }

  .scene-svg svg {
    max-height: 45vh;
  }

  .nav-dots {
    right: 0.75rem;
    gap: 1rem;
  }

  .nav-tooltip {
    display: none;
  }
}

@media (max-width: 600px) {
  .scene-inner {
    width: min(92%, 1280px);
    gap: 2rem;
    padding: 3rem 0;
  }

  .scene-label {
    font-size: clamp(2.5rem, 10vw, 4rem);
  }

  .scene-title {
    font-size: clamp(1.4rem, 6vw, 2rem);
  }

  .scene-desc {
    font-size: 0.88rem;
  }

  .scene-svg svg {
    max-height: 35vh;
  }

  .hero-title {
    width: min(92%, 520px);
  }

  .nav-dots {
    right: 0.4rem;
    gap: 0.8rem;
  }

  .nav-dot {
    width: 8px;
    height: 8px;
  }

  .scroll-arrow {
    display: none;
  }
}

/* ── Reduced Motion ──────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }

  .hero-letter {
    stroke-dashoffset: 0 !important;
  }

  .hero-fade {
    opacity: 1 !important;
    transform: none !important;
  }

  [data-draw] {
    stroke-dashoffset: 0 !important;
  }
}