/* ───────────── Tokens ───────────── */
:root {
  --bg: #f5f5f7;
  --card: #ffffff;
  --fill: rgba(118, 118, 128, 0.12);   /* iOS tertiary fill */
  --ink: #1d1d1f;
  --ink-2: #424245;
  --muted: #6e6e73;
  --hairline: #d2d2d7;
  --accent: #ff5b2e;
  --accent-2: #ff2d55;
  --accent-soft: #fff0ea;
  --good: #1a9a55;
  --bad: #e0301e;

  --dark: #000000;
  --dark-card: #1d1d1f;
  --dark-rule: #333336;
  --dark-ink: #f5f5f7;
  --dark-muted: #86868b;
  --term-green: #30d158;
  --term-amber: #ffd60a;
  --term-blue: #64d2ff;

  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --display: var(--sans);
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;

  /* Critically damped spring (damping 1.0, response 0.4s), sampled for CSS */
  --spring: linear(0, 0.001 0.5%, 0.0085 1.5%, 0.0286 2.8%, 0.0652 4.4%, 0.1189 6.4%, 0.1879 8.5%, 0.2687 10.9%, 0.3565 13.5%, 0.4465 16.3%, 0.5344 19.3%, 0.6167 22.4%, 0.691 25.8%, 0.7558 29.3%, 0.8108 33%, 0.8561 36.8%, 0.8925 40.8%, 0.9211 45%, 0.9431 49.3%, 0.9596 53.8%, 0.9718 58.4%, 0.9806 63.1%, 0.9869 68%, 0.9912 73%, 0.9942 78.1%, 0.9963 83.4%, 0.9985 94.3%, 1);
  --spring-dur: 0.6s;

  --wrap: 72rem;
  --gutter: clamp(1rem, 4vw, 2.5rem);
  --rail-offset: 14px; /* node centre from the text column's left edge */
  --nav-h: 3.25rem;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 1.0625rem/1.5 var(--sans);     /* 17px — Apple's body size */
  letter-spacing: -0.012em;           /* Inter's recommended tracking at 17px */
  font-optical-sizing: auto;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; }
code { font-family: var(--mono); font-size: 0.85em; letter-spacing: 0; }
/* no orphaned last words; headings break into even lines */
p, li, figcaption, .hero-stats span { text-wrap: pretty; }
h1, h2, h3, .band-title { text-wrap: balance; }
[hidden] { display: none !important; }

.wrap {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* Instant press feedback on everything tappable */
.toggle-btn, .nav-cta, .contact-links a, .nav-mark {
  transition: transform 100ms ease-out, background-color 0.2s, color 0.2s, opacity 0.2s;
  -webkit-tap-highlight-color: transparent;
}
.toggle-btn:active, .nav-cta:active, .contact-links a:active, .nav-mark:active { transform: scale(0.96); }

/* ───────────── Nav: translucent material that materialises on scroll ───────────── */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  height: calc(var(--nav-h) + env(safe-area-inset-top, 0px));
  padding: env(safe-area-inset-top, 0px) var(--gutter) 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--ink);
  transition: color 0.5s ease;
}
.nav::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: rgba(245, 245, 247, 0.72);
  backdrop-filter: blur(0px) saturate(100%);
  -webkit-backdrop-filter: blur(0px) saturate(100%);
  opacity: 0;
  /* scroll-edge effect: soft fade at the bottom instead of a hard divider */
  -webkit-mask-image: linear-gradient(#000 calc(100% - 10px), transparent);
  mask-image: linear-gradient(#000 calc(100% - 10px), transparent);
  transition: opacity 0.45s ease, backdrop-filter 0.45s ease, -webkit-backdrop-filter 0.45s ease, background-color 0.5s ease;
}
.nav.is-scrolled::before {
  opacity: 1;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
}
.nav.is-dark { color: var(--dark-ink); }
.nav.is-dark::before { background: rgba(22, 22, 23, 0.72); }

.nav-mark {
  font: 600 1.25rem/1 var(--display);
  letter-spacing: -0.03em;
  text-decoration: none;
}
.nav-cta {
  font: 500 0.8125rem/1 var(--sans);
  letter-spacing: -0.01em;
  text-decoration: none;
  padding: 0.5rem 0.9rem;
  border-radius: 980px;
  background: var(--ink);
  color: var(--bg);
}
.nav-cta:hover { background: #000; }
.nav.is-dark .nav-cta { background: var(--dark-ink); color: var(--dark); }

/* iOS segmented control — a solid fill, so it never stacks glass on glass */
.toggle {
  position: relative;
  display: flex;
  padding: 2px;
  border-radius: 9px;
  background: var(--fill);
  transition: background-color 0.5s ease;
}
.toggle-btn {
  position: relative;
  z-index: 1;
  min-width: 5.5rem;
  padding: 0.35rem 1rem;
  text-align: center;
  font: 500 0.8125rem/1.2 var(--sans);
  letter-spacing: -0.01em;
  text-decoration: none;
  color: var(--ink);
  border-radius: 7px;
}
.toggle-btn.is-active { font-weight: 600; }
.toggle-pill {
  position: absolute;
  top: 2px;
  bottom: 2px;
  left: 0;
  width: 0;
  border-radius: 7px;
  background: #fff;
  box-shadow: 0 3px 8px rgba(0, 0, 0, 0.12), 0 3px 1px rgba(0, 0, 0, 0.04);
  will-change: transform, width;
  transition: background-color 0.5s ease;
}
.nav.is-dark .toggle { background: rgba(118, 118, 128, 0.24); }
.nav.is-dark .toggle-btn { color: var(--dark-ink); }
.nav.is-dark .toggle-pill { background: #636366; box-shadow: 0 3px 8px rgba(0, 0, 0, 0.3); }

/* ───────────── Journey + thread ───────────── */
.journey { position: relative; }
.thread {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  pointer-events: none;
  overflow: visible;
}
.thread path { fill: none; stroke-linecap: round; stroke-linejoin: round; }
.thread-ghost { stroke: var(--hairline); stroke-width: 1.5; stroke-dasharray: 1 7; }
.thread-live { stroke: url(#threadGrad); stroke-width: 2.5; }
#threadGrad stop { stop-color: var(--accent); }
#threadGrad stop:nth-child(n + 3) { stop-color: var(--term-green); }
.thread-tip {
  fill: var(--accent);
  stroke: var(--bg);
  stroke-width: 3;
  transition: fill 0.4s, stroke 0.4s;
}
.thread-tip.is-dark { fill: var(--term-green); stroke: var(--dark); }

.hero, .chapter .wrap, .contact { position: relative; z-index: 2; }

.node {
  position: absolute;
  left: calc(var(--rail-offset) - 7px);
  top: 4px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--bg);
  border: 1.5px solid var(--hairline);
  transition: border-color 0.3s, background-color 0.3s, box-shadow var(--spring-dur) var(--spring), transform var(--spring-dur) var(--spring);
}
.node.is-lit {
  border-color: var(--accent);
  background: var(--accent);
  box-shadow: 0 0 0 5px rgba(255, 91, 46, 0.16);
  transform: scale(1.1);
}
.chapter--origins .node { background: var(--dark); border-color: var(--dark-rule); }
.chapter--origins .node.is-lit {
  border-color: var(--term-green);
  background: var(--term-green);
  box-shadow: 0 0 0 5px rgba(48, 209, 88, 0.18);
}

/* ───────────── Type scale — tracking tightens as size grows ───────────── */
.eyebrow, .kicker {
  font: 600 0.75rem/1.33 var(--sans);
  letter-spacing: 0.01em;
  color: var(--muted);
  margin: 0 0 0.75rem;
}
.kicker { color: var(--accent); }

/* ───────────── Hero ───────────── */
.hero {
  min-height: min(100svh, 960px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding-block: 7rem 4rem;
}
.hero > * { animation: rise var(--spring-dur) var(--spring) both; }
.hero > :nth-child(2) { animation-delay: 60ms; }
.hero > :nth-child(3) { animation-delay: 120ms; }
.hero > :nth-child(4) { animation-delay: 180ms; }
.hero > :nth-child(5) { animation-delay: 240ms; }
@keyframes rise { from { opacity: 0; transform: translateY(24px); } }

.hero .eyebrow { font-size: 1.1875rem; font-weight: 600; letter-spacing: 0.009em; color: var(--ink); margin-bottom: 0.5rem; }
.hero-title {
  font: 700 clamp(4rem, 11vw, 8.5rem)/1 var(--display);
  letter-spacing: -0.035em;
  margin: 0 0 1.5rem;
}
.hero-lede {
  font: 600 clamp(1.5rem, 3vw, 2.5rem)/1.12 var(--display);
  letter-spacing: -0.022em;
  color: var(--ink);
  max-width: 24ch;
  margin: 0 0 3.5rem;
}
.grad {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-stats {
  list-style: none;
  padding: 0;
  margin: 0 0 4rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}
.hero-stats li {
  padding: 1.5rem;
  border-radius: 18px;
  background: var(--card);
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}
.hero-stats strong { font: 700 clamp(1.75rem, 3vw, 2.5rem)/1.05 var(--display); letter-spacing: -0.025em; }
.hero-stats span { font-size: 0.9375rem; line-height: 1.4; letter-spacing: -0.01em; color: var(--muted); }
.hero-start { position: relative; padding-left: 44px; min-height: 22px; }
.hero-cue { font: 500 0.875rem/22px var(--sans); color: var(--muted); letter-spacing: -0.01em; }
.node--start { border-color: var(--accent); }

/* ───────────── Stops ───────────── */
.chapter { position: relative; padding-block: 3.5rem 2.5rem; }
.stop {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(2.5rem, 6vw, 5.5rem);
  align-items: start;
  margin-bottom: clamp(8.5rem, 16vw, 12.5rem);
}
.stop[data-side="right"] .stop-text { grid-column: 2; grid-row: 1; }
.stop[data-side="right"] .stop-visual { grid-column: 1; grid-row: 1; }
.stop--intro { grid-template-columns: minmax(0, 1fr); max-width: 46rem; }

.stop-text { position: relative; padding-left: 44px; }
.stop-text h3 {
  font: 700 clamp(2rem, 3.6vw, 3rem)/1.08 var(--display);
  letter-spacing: -0.026em;
  margin: 0 0 1.1rem;
}
.stop-text h3 small {
  display: block;
  margin-top: 0.4rem;
  font: 500 0.9375rem/1.3 var(--sans);
  letter-spacing: -0.01em;
  color: var(--muted);
}
.chapter-title {
  font: 700 clamp(3.5rem, 8vw, 6rem)/1 var(--display);
  letter-spacing: -0.035em;
  margin: 0 0 1.25rem;
}
.lede { margin: 0 0 1.5rem; color: var(--ink-2); max-width: 36em; }
.lede b { color: var(--ink); font-weight: 600; }

.facts { list-style: none; padding: 0; margin: 0 0 1.5rem; }
.facts li {
  display: grid;
  grid-template-columns: 6rem 1fr;
  gap: 0.75rem;
  padding: 0.75rem 0;
  border-top: 1px solid var(--hairline);
  font-size: 0.9375rem;
  letter-spacing: -0.012em;
}
.facts li:last-child { border-bottom: 1px solid var(--hairline); }
.facts li span { font-weight: 600; color: var(--muted); font-size: 0.8125rem; line-height: 1.8; letter-spacing: 0; }
.facts b { font-weight: 600; }
.tags { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.tags span {
  font: 500 0.8125rem/1 var(--sans);
  letter-spacing: -0.005em;
  padding: 0.45rem 0.8rem;
  border-radius: 980px;
  background: var(--fill);
  color: var(--ink-2);
}

.stop-visual { margin: 0; position: sticky; top: calc(var(--nav-h) + 3rem); }
.stop-visual figcaption {
  margin-top: 0.75rem;
  font-size: 0.75rem;
  letter-spacing: 0;
  color: var(--muted);
}

/* Scroll-scrubbed reveal: JS writes --p (0 → 1) as the visual enters, so it's fully reversible */
.reveal {
  --p: 1;
  opacity: calc(0.15 + var(--p) * 0.85);
  transform: translateY(calc((1 - var(--p)) * 48px)) scale(calc(0.94 + var(--p) * 0.06));
  transform-origin: 50% 100%;
  will-change: transform, opacity;
}

/* ───────────── Shared card surface ───────────── */
.browser, .dag, .chat, .ph-map {
  border-radius: 22px;
  background: var(--card);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.03), 0 24px 48px -24px rgba(0, 0, 0, 0.18);
}

/* ───────────── Browser frame ───────────── */
.browser { overflow: hidden; }
.browser-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 0.7rem 1rem;
  background: #f0f0f2;
}
.browser-bar i { width: 11px; height: 11px; border-radius: 50%; background: #ff5f57; }
.browser-bar i:nth-child(2) { background: #febc2e; }
.browser-bar i:nth-child(3) { background: #28c840; }
.browser-bar span { margin-inline: auto; padding-right: 40px; font-size: 0.75rem; color: var(--muted); letter-spacing: 0; }

/* ───────────── Featured stop: eval platform showcase ───────────── */
.stop--feature { grid-template-columns: minmax(0, 1fr); }
.feature-head {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: clamp(2rem, 5vw, 4.5rem);
  align-items: end;
}
.feature-head .facts { margin-top: 0; }

/* Tall track; the inner frame pins while the page scrolls through it */
.feature-stage { position: relative; height: 190vh; margin: 3rem 0 0 44px; }
.feature-sticky {
  position: sticky;
  top: calc(var(--nav-h) + 1.25rem);
  display: grid;
  justify-items: center;
  gap: 1rem;
}
.feature-frame { width: min(100%, calc((100svh - var(--nav-h) - 10.5rem) * 1.786)); transform-origin: 50% 0; }
.browser--dark { background: #0d0d10; box-shadow: 0 2px 6px rgba(0, 0, 0, 0.06), 0 40px 80px -40px rgba(0, 0, 0, 0.55); }
.browser--dark .browser-bar { background: #1c1c1e; }
.browser--dark .browser-bar span { color: #8e8e93; }
.feature-shots { position: relative; aspect-ratio: 2826 / 1582; background: #0d0d10; }
.feature-shots img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  opacity: 0;
  transform: scale(1.015);
  transition: opacity 0.5s ease, transform var(--spring-dur) var(--spring);
}
.feature-shots img.is-active { opacity: 1; transform: none; }

.feature-caption { display: grid; max-width: 44rem; margin: 0; text-align: center; font-size: 0.9375rem; color: var(--muted); letter-spacing: -0.012em; }
.feature-caption span { grid-area: 1 / 1; opacity: 0; transform: translateY(6px); transition: opacity 0.4s ease, transform var(--spring-dur) var(--spring); }
.feature-caption span.is-active { opacity: 1; transform: none; }
.feature-caption b { color: var(--ink); font-weight: 600; }

/* In-section segmented control (same material as the nav one) */
.seg { position: relative; display: flex; padding: 2px; border-radius: 9px; background: var(--fill); }
.seg-btn {
  position: relative;
  z-index: 1;
  min-width: 9rem;
  padding: 0.4rem 1rem;
  border: 0;
  background: none;
  font: 500 0.8125rem/1.2 var(--sans);
  letter-spacing: -0.01em;
  color: var(--ink);
  cursor: pointer;
  border-radius: 7px;
  transition: transform 100ms ease-out;
  -webkit-tap-highlight-color: transparent;
}
.seg-btn:active { transform: scale(0.96); }
.seg-btn.is-active { font-weight: 600; }
.seg-pill {
  position: absolute;
  top: 2px;
  bottom: 2px;
  left: 0;
  width: 0;
  border-radius: 7px;
  background: #fff;
  box-shadow: 0 3px 8px rgba(0, 0, 0, 0.12), 0 3px 1px rgba(0, 0, 0, 0.04);
  will-change: transform, width;
}

/* ───────────── Visual: control tower ───────────── */
.ct {
  background: var(--dark-card);
  color: var(--dark-ink);
  border-radius: 22px;
  padding: 1.1rem;
  display: grid;
  gap: 0.7rem;
  font-size: 0.8125rem;
  box-shadow: 0 24px 48px -24px rgba(0, 0, 0, 0.45);
}
.ct-top { display: flex; justify-content: space-between; font-size: 0.875rem; }
.ct-top b { font-weight: 600; }
.ct-top .live { font-size: 0.6875rem; color: var(--term-green); font-weight: 600; }
.ct-kpis { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.5rem; }
.ct-kpis div { background: #2c2c2e; border-radius: 12px; padding: 0.65rem 0.75rem; }
.ct-kpis small { display: block; font-size: 0.6875rem; color: var(--dark-muted); font-weight: 500; }
.ct-kpis b { font: 700 1.5rem/1.15 var(--display); letter-spacing: -0.022em; }
.ct-kpis em { font: normal 600 0.6875rem var(--sans); margin-left: 3px; }
.ct-kpis .up { color: var(--term-green); }
.ct-kpis .dn { color: #ff6961; }
.ct-chart { background: #2c2c2e; border-radius: 12px; padding: 0.75rem 0.6rem 0.4rem; height: 7.5rem; }
.ct-chart svg { width: 100%; height: 100%; }
.bars rect { fill: #48484a; rx: 3px; transform-origin: bottom; transform-box: fill-box; transform: scaleY(0.04); transition: transform var(--spring-dur) var(--spring); }
.bars rect.hot { fill: var(--accent); }
.is-in .bars rect { transform: none; }
.is-in .bars rect:nth-child(2) { transition-delay: 40ms; } .is-in .bars rect:nth-child(3) { transition-delay: 80ms; }
.is-in .bars rect:nth-child(4) { transition-delay: 120ms; } .is-in .bars rect:nth-child(5) { transition-delay: 160ms; }
.is-in .bars rect:nth-child(6) { transition-delay: 200ms; } .is-in .bars rect:nth-child(7) { transition-delay: 240ms; }
.is-in .bars rect:nth-child(8) { transition-delay: 280ms; } .is-in .bars rect:nth-child(9) { transition-delay: 320ms; }
.is-in .bars rect:nth-child(10) { transition-delay: 360ms; }
.ct-alert {
  padding: 0.65rem 0.8rem;
  border-radius: 12px;
  background: rgba(255, 91, 46, 0.16);
  opacity: 0;
  transform: translateY(-8px) scale(0.97);
  transition: opacity 0.4s ease 0.7s, transform var(--spring-dur) var(--spring) 0.7s;
}
.ct-alert b { color: #ff8a65; font-weight: 600; margin-right: 4px; }
.is-in .ct-alert { opacity: 1; transform: none; }
.ct-chat { display: grid; gap: 0.35rem; }
.ct-chat p { margin: 0; padding: 0.55rem 0.8rem; border-radius: 18px; max-width: 86%; }
.ct-chat .q { justify-self: end; background: #0071e3; color: #fff; border-bottom-right-radius: 6px; }
.ct-chat .a { background: #3a3a3c; border-bottom-left-radius: 6px; }
.ct-chat code { font-size: 0.625rem; padding: 2px 5px; border-radius: 5px; background: #48484a; color: var(--term-green); margin-left: 4px; }

/* ───────────── Visual: DAG ───────────── */
.dag { padding: 1.1rem; }
.dag svg { width: 100%; height: auto; display: block; }
.dag-edges path { fill: none; stroke: #c7c7cc; stroke-width: 2; stroke-dasharray: 400; stroke-dashoffset: 400; transition: stroke-dashoffset 1.2s cubic-bezier(0.25, 0.1, 0.25, 1); }
.dag-edges path.out { stroke: var(--accent); transition-delay: 0.5s; }
.is-in .dag-edges path { stroke-dashoffset: 0; }
.dag-packets circle { fill: var(--ink); opacity: 0; transition: opacity 0.4s 1.2s; }
.dag-packets circle.out { fill: var(--accent); }
.is-in .dag-packets circle { opacity: 1; }
.dag-nodes rect { fill: #f5f5f7; stroke: none; }
.dag-nodes .core rect { fill: var(--ink); }
.dag-nodes .sink rect { fill: var(--accent-soft); stroke: var(--accent); stroke-width: 1.2; }
.dag-nodes text { font: 600 12.5px var(--sans); letter-spacing: -0.01em; text-anchor: middle; fill: var(--ink); }
.dag-nodes .core text { fill: #fff; }
.dag-nodes text.sub { font-size: 10px; font-weight: 500; fill: var(--muted); }
.dag-nodes .sink text.sub { fill: #c2410c; }
.dag-nodes .core-step rect { fill: #2c2c2e; }
.dag-nodes .core-title { font: 700 20px var(--display); letter-spacing: -0.03em; }
.dag-nodes .core-sub { font-size: 10px; font-weight: 500; fill: #8e8e93 !important; }

/* ───────────── Logo band: who runs on Setu ───────────── */
.stop-band {
  grid-column: 1 / -1;
  margin-left: 44px;
  display: grid;
  gap: 1.75rem;
  padding: clamp(1.5rem, 3vw, 2.5rem);
  border-radius: 22px;
  background: var(--card);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.03), 0 24px 48px -24px rgba(0, 0, 0, 0.14);
}
.band-head .kicker { margin-bottom: 0.4rem; }
.band-title {
  margin: 0;
  max-width: 34ch;
  font: 600 clamp(1.25rem, 2.2vw, 1.75rem)/1.2 var(--display);
  letter-spacing: -0.025em;
}
/* monochrome at rest, full colour when you engage with it */
.band-logos {
  width: 100%;
  height: auto;
  filter: grayscale(1) contrast(1.1);
  opacity: 0.72;
  mix-blend-mode: multiply;
  transition: filter 0.6s ease, opacity 0.6s ease;
}
.stop-band:hover .band-logos, .stop-band:focus-within .band-logos { filter: none; opacity: 1; }
.band-stats { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.75rem; }
.band-stats div { display: flex; align-items: baseline; gap: 0.75rem; padding: 1.1rem 1.25rem; border-radius: 16px; background: var(--bg); }
.band-stats b { font: 700 clamp(2rem, 4vw, 2.75rem)/1 var(--display); letter-spacing: -0.03em; }
.band-stats span { font-size: 0.9375rem; color: var(--muted); letter-spacing: -0.01em; }

/* ───────────── Visual: Philippines map ───────────── */
.ph-map {
  position: relative;
  aspect-ratio: 4 / 5;
  overflow: hidden;
  background: radial-gradient(120% 90% at 60% 35%, #ffffff 0%, #eef1f5 70%);
}
.ph-map svg { position: absolute; inset: 0; width: 100%; height: 100%; }
.ph-dot { fill: #b8bcc6; }
.ph-route { fill: none; stroke: var(--ink); stroke-width: 1.3; stroke-dasharray: 2 5; opacity: 0.45; }
.ph-route.sea { stroke: #0a84ff; opacity: 0.6; }
.ph-hub { fill: var(--accent); }
.ph-pulse { fill: none; stroke: var(--accent); stroke-width: 1.5; transform-box: fill-box; transform-origin: center; animation: pulse 2.4s ease-out infinite; }
.ph-hub-label { font: 700 10px var(--sans); fill: var(--ink); letter-spacing: 0.02em; }
.truck-body { fill: var(--ink); }
.truck-cab { fill: var(--accent); }
@keyframes pulse { from { transform: scale(1); opacity: 0.9; } to { transform: scale(3.2); opacity: 0; } }

.map-tag {
  position: absolute;
  left: var(--x);
  top: var(--y);
  transform: translate(-50%, -50%) translateY(10px) scale(0.96);
  opacity: 0;
  white-space: nowrap;
  font: 600 0.75rem/1 var(--sans);
  letter-spacing: -0.01em;
  padding: 0.5rem 0.75rem;
  border-radius: 980px;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.06), 0 8px 20px -8px rgba(0, 0, 0, 0.2);
  transition: opacity 0.4s ease, transform var(--spring-dur) var(--spring);
}
.is-in .map-tag { opacity: 1; transform: translate(-50%, -50%); }
.is-in .map-tag:nth-of-type(2) { transition-delay: 0.1s; }
.is-in .map-tag:nth-of-type(3) { transition-delay: 0.2s; }
.is-in .map-tag:nth-of-type(4) { transition-delay: 0.3s; }
.is-in .map-tag:nth-of-type(5) { transition-delay: 0.4s; }
.is-in .map-tag:nth-of-type(n + 6) { transition-delay: 0.5s; }

/* ───────────── Visual: chat ───────────── */
.chat { padding: 1.1rem; display: grid; gap: 0.5rem; font-size: 0.875rem; letter-spacing: -0.012em; }
.chat-top { display: flex; align-items: center; gap: 0.5rem; padding-bottom: 0.7rem; border-bottom: 1px solid #ececf0; }
.chat-top b { font-weight: 600; }
.chat-top small { margin-left: auto; font-size: 0.6875rem; color: var(--muted); }
.bot-dot { width: 10px; height: 10px; border-radius: 50%; background: #d97757; box-shadow: 0 0 0 4px rgba(217, 119, 87, 0.18); }
.msg { margin: 0; padding: 0.6rem 0.85rem; border-radius: 18px; max-width: 86%; line-height: 1.4; }
.msg.me { justify-self: end; background: #0071e3; color: #fff; border-bottom-right-radius: 6px; }
.msg.bot { background: #e9e9eb; border-bottom-left-radius: 6px; }
.chat-stat { font-size: 0.8125rem; color: var(--muted); padding-top: 0.4rem; }
.chat-stat b { font: 700 1.75rem/1 var(--display); letter-spacing: -0.025em; color: var(--ink); margin-right: 6px; }

/* ═════════════ Origins chapter (dark) ═════════════ */
.chapter--origins {
  --fade: 16rem;  /* eased light → dark band instead of an abrupt brightness jump */
  background: linear-gradient(var(--bg), var(--dark) var(--fade)) no-repeat, var(--dark);
  color: var(--dark-ink);
  padding-top: calc(var(--fade) + 2rem);
}
.chapter--origins .kicker { color: var(--term-green); font-family: var(--mono); font-weight: 500; }
.chapter--origins .chapter-title { font-family: var(--mono); font-weight: 600; font-size: clamp(3rem, 7vw, 5.5rem); letter-spacing: -0.06em; }
.chapter--origins .chapter-title::after { content: "_"; color: var(--term-green); animation: blink 1.1s steps(1) infinite; }
.chapter--origins .stop-text h3 { font-family: var(--mono); font-weight: 600; font-size: clamp(1.375rem, 2.4vw, 1.75rem); letter-spacing: -0.04em; }
.chapter--origins .stop-text h3 small { color: var(--dark-muted); font-family: var(--sans); }
.chapter--origins .lede { color: #a1a1a6; }
.chapter--origins .lede b { color: var(--dark-ink); }
.stop--compact { margin-bottom: clamp(5.5rem, 10vw, 8rem); }
.stop--compact .stop-visual { position: static; }
/* A sticky element pins until the end of its parent, so with a full-width band in the same stop
   the visual would ride down over the band. Stops with a band keep their visual in flow. */
.stop--banded .stop-visual { position: static; }
@keyframes blink { 50% { opacity: 0; } }

.term {
  margin: 0;
  background: var(--dark-card);
  border-radius: 18px;
  padding: 1.1rem 1.25rem;
  font: 0.8125rem/1.75 var(--mono);
  letter-spacing: 0;
  color: var(--dark-ink);
  overflow-x: auto;
  white-space: pre;
}
.term .c { color: #8e8e93; }
.term .p { color: var(--term-green); }
.term .s { color: var(--term-amber); }
.term .o { color: var(--term-blue); }
.term--stat { display: flex; align-items: baseline; gap: 0.9rem; white-space: normal; padding: 1.6rem 1.5rem; }
.term--stat b { font: 700 clamp(3rem, 6vw, 4.5rem)/1 var(--display); color: var(--term-green); letter-spacing: -0.035em; }
.term--stat span { color: var(--dark-muted); font: 0.9375rem var(--sans); letter-spacing: -0.01em; }

.chapter--origins .tags span { background: var(--dark-card); color: #a1a1a6; }
.paper-link {
  display: inline-block;
  margin-top: 1.25rem;
  font: 600 0.9375rem/1 var(--sans);
  letter-spacing: -0.01em;
  text-decoration: none;
  padding: 0.8rem 1.2rem;
  border-radius: 980px;
  background: var(--dark-ink);
  color: var(--dark);
  transition: transform 100ms ease-out, background-color 0.2s;
}
.paper-link:hover { background: #fff; }
.paper-link:active { transform: scale(0.96); }

.paper-shot { display: block; text-decoration: none; transition: transform var(--spring-dur) var(--spring); }
.paper-shot:hover { transform: translateY(-4px); }
.paper-shot:active { transform: scale(0.98); transition-duration: 100ms; }
.paper-shot .browser { box-shadow: 0 30px 60px -30px rgba(0, 0, 0, 0.9); }
.paper-shot img { width: 100%; height: auto; padding: 0.6rem 0.9rem 0.4rem; background: #fff; }
.chapter--origins .facts li { border-color: var(--dark-rule); }
.chapter--origins .facts li span { color: var(--dark-muted); }
.chapter--origins .facts b { color: var(--dark-ink); }

.stop--roots { grid-template-columns: minmax(0, 1fr); margin-bottom: 7.5rem; }
.roots { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0.75rem; }
.roots div { padding: 1.25rem; border-radius: 18px; background: var(--dark-card); display: flex; flex-direction: column; gap: 0.35rem; }
.roots b { font-weight: 600; font-size: 0.9375rem; }
.roots span { font-size: 0.875rem; color: var(--dark-muted); letter-spacing: -0.01em; }

.contact { padding-block: 4rem 6rem; }
.contact h2 { font: 700 clamp(2.75rem, 7vw, 5.5rem)/1.02 var(--display); letter-spacing: -0.035em; margin: 0 0 1.75rem; color: var(--dark-ink); }
.contact-links { display: flex; flex-wrap: wrap; gap: 0.75rem; }
.contact-links a {
  font: 500 0.9375rem/1 var(--sans);
  letter-spacing: -0.01em;
  text-decoration: none;
  padding: 0.85rem 1.25rem;
  border-radius: 980px;
  background: var(--dark-card);
}
.contact-links a:first-child { background: var(--dark-ink); color: var(--dark); }
.contact-links a:hover { background: #2c2c2e; }
.contact-links a:first-child:hover { background: #fff; }

/* ───────────── Responsive ───────────── */
@media (max-width: 860px) {
  .stop,
  .stop[data-side="right"] { grid-template-columns: minmax(0, 1fr); gap: 2rem; }
  .stop[data-side="right"] .stop-text,
  .stop[data-side="right"] .stop-visual { grid-column: 1; grid-row: auto; }
  .stop-visual { position: static; margin-left: 44px; }
  .hero-stats, .roots { grid-template-columns: minmax(0, 1fr); }
  .feature-head { grid-template-columns: minmax(0, 1fr); gap: 0; }
  /* no pinning on small screens: both views simply stack */
  .feature-stage { height: auto; margin-top: 2rem; }
  .feature-sticky { position: static; }
  .seg, .feature-caption { display: none; }
  .feature-frame { width: 100%; }
  .feature-shots { aspect-ratio: auto; display: grid; gap: 2px; }
  .feature-shots img { position: static; opacity: 1; transform: none; height: auto; }
  .toggle-btn { min-width: 4.5rem; padding-inline: 0.75rem; }
}
@media (max-width: 480px) {
  :root { --rail-offset: 10px; }
  .stop-text, .hero-start { padding-left: 32px; }
  .stop-visual, .feature-stage, .stop-band { margin-left: 32px; }
  .band-stats { grid-template-columns: minmax(0, 1fr); }
  .facts li { grid-template-columns: 1fr; gap: 2px; }
  .nav-mark { display: none; }
}

/* ───────────── Accessibility preferences ───────────── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero > * { animation: none; }
  .reveal { --p: 1 !important; transform: none; }
  .map-tag, .ct-alert, .bars rect, .node, .feature-shots img, .feature-caption span { transition: opacity 0.2s ease !important; }
  .feature-shots img, .feature-caption span { transform: none; }
  .map-tag, .is-in .map-tag { transform: translate(-50%, -50%); }
  .ct-alert, .bars rect { transform: none; }
  .dag-edges path { transition: none; stroke-dashoffset: 0; }
  .ph-pulse, .chapter--origins .chapter-title::after { animation: none; }
}
@media (prefers-reduced-transparency: reduce) {
  .nav::before { background: var(--bg); backdrop-filter: none !important; -webkit-backdrop-filter: none !important; }
  .nav.is-dark::before { background: #161617; }
  .map-tag { background: #fff; }
}
@media (prefers-contrast: more) {
  :root { --muted: #3a3a3c; --hairline: #8e8e93; --fill: rgba(118, 118, 128, 0.28); }
  .nav::before { background: var(--bg); backdrop-filter: none; -webkit-backdrop-filter: none; box-shadow: 0 1px 0 var(--ink); }
  .browser, .dag, .chat, .ph-map, .hero-stats li, .stop-band { box-shadow: none; outline: 1px solid var(--ink); }
  .band-logos { filter: none; opacity: 1; }
  .chapter--origins .lede, .roots span { color: #d1d1d6; }
}