:root {
  --bg: #f4f7fb;
  --paper: #ffffff;
  --ink: #172033;
  --muted: #617089;
  --line: #d7e0ea;
  --blue: #159bd7;
  --blue-dark: #1c67b6;
  --orange: #e69600;
  --pink: #ff5579;
  --dark: #121a2a;
  --dark-2: #1b263b;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
img { display: block; max-width: 100%; }
.shell { width: min(calc(100% - 48px), var(--max)); margin: 0 auto; }
.shell.narrow { max-width: 900px; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
  padding: 0 max(24px, calc((100vw - var(--max)) / 2));
  background: rgba(244,247,251,.92);
  border-bottom: 1px solid rgba(215,224,234,.9);
  backdrop-filter: blur(14px);
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 850;
  font-size: 19px;
  letter-spacing: -.02em;
}
.brand-icon { width: 31px; height: 31px; flex: 0 0 auto; color: #c9d5e1; }
.nav { display: flex; gap: 27px; font-size: 14px; color: #445168; }
.nav a:hover { color: var(--ink); }

.hero { padding: 88px 0 76px; text-align: center; }
.eyebrow, .section-kicker, .mini-label, .method-step, .bridge-label, .result-tag {
  font: 700 10px/1.3 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: #7a8aa3;
}
.hero h1 {
  margin: 12px 0 8px;
  font-size: clamp(72px, 10vw, 124px);
  line-height: .9;
  letter-spacing: -.075em;
}
.hero-subtitle {
  max-width: 940px;
  margin: 20px auto 0;
  color: #4d5c73;
  font-size: clamp(22px, 3vw, 31px);
  line-height: 1.28;
  letter-spacing: -.03em;
}
.authors { display: flex; justify-content: center; gap: 12px; margin-top: 31px; font-size: 18px; font-weight: 680; }
.author-sep { color: #a8b3c2; }
.affiliation { margin-top: 8px; color: #8694a8; }
.hero-actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 11px; margin-top: 31px; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 112px;
  padding: 11px 18px;
  border: 1px solid #b9c6d5;
  border-radius: 999px;
  background: white;
  font-weight: 760;
  font-size: 14px;
  transition: .16s ease;
}
.button:hover { transform: translateY(-1px); border-color: #7c8da5; }
.button.primary { background: var(--ink); border-color: var(--ink); color: white; }
.button[aria-disabled="true"] { opacity: .45; pointer-events: none; }
.button-icon { width: 17px; height: 17px; margin-right: 8px; flex: 0 0 auto; }

.rounding-card {
  margin-top: 62px;
  padding: 32px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: 26px;
  background: var(--paper);
  box-shadow: 0 15px 48px rgba(50, 71, 101, .07);
}
.rounding-card-head { display: grid; grid-template-columns: 1.15fr .85fr; gap: 42px; align-items: end; }
.rounding-card-head h2 {
  margin: 7px 0 0;
  max-width: 680px;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.04;
  letter-spacing: -.045em;
}
.rounding-card-head p { margin: 0; color: var(--muted); line-height: 1.6; font-size: 16px; }

.scale-wrap {
  margin-top: 35px;
  padding: 62px 76px 82px;
  border-radius: 19px;
  background: #f7f9fc;
  border: 1px solid #e2e8f0;
}
.scale-track { position: relative; height: 62px; border-top: 3px solid #7a879b; }
.endpoint-group {
  position: absolute;
  top: -22px;
  width: 104px;
  display: flex;
  flex-direction: column;
  align-items: center;
  z-index: 3;
}
.endpoint-group-left { left: -52px; }
.endpoint-group-right { right: -52px; }
.endpoint {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  background: #e9eff6;
  border-radius: 13px;
  font-weight: 850;
  font-size: 17px;
}
.endpoint-note {
  margin-top: 7px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1px;
  color: #718098;
  font-size: 12px;
  line-height: 1.25;
  text-align: center;
  white-space: nowrap;
}
.endpoint-note strong { color: #4c5a70; font-size: 12px; font-weight: 800; }
.mid-tick { position: absolute; left: 50%; top: -24px; width: 3px; height: 49px; background: #6f7d91; }
.mid-label { position: absolute; left: 50%; top: 31px; transform: translateX(-50%); color: #708099; font-weight: 700; font-size: 13px; white-space: nowrap; }
.scaled-dot, .recon-dot {
  position: absolute;
  top: -14px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  border: 3px solid #2d3648;
  transform: translateX(-50%);
  z-index: 4;
}
.scaled-dot { left: 48%; background: var(--orange); }
.recon-dot { left: 76%; background: var(--pink); }
.scaled-dot-label, .recon-dot-label {
  position: absolute;
  top: -49px;
  transform: translateX(-50%);
  white-space: nowrap;
  font-size: 13px;
  font-weight: 800;
}
.scaled-dot-label { left: 48%; color: #c97a00; }
.recon-dot-label { left: 76%; color: #eb496b; }

.decision-row { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 18px; margin-top: 23px; }
.decision-box { padding: 23px; border-radius: 18px; border: 1px solid #dce4ed; background: #fafbfd; }
.reround-box { background: #fff8fa; border-color: #ffd0da; }
.decision-pill { display: inline-block; padding: 5px 9px; border-radius: 999px; background: #e9eef5; color: #4c596f; font-size: 10px; font-weight: 850; }
.pink-pill { background: #ffe1e8; color: #c8395a; }
.decision-box h3 { margin: 14px 0 8px; font-size: 19px; letter-spacing: -.02em; }
.decision-box p { margin: 0; color: var(--muted); line-height: 1.58; }

.section { padding: 102px 0; scroll-margin-top: 68px; }
.section-kicker { margin-bottom: 20px; }
.section-kicker.light { color: #8fa0b9; }
.section h2 { margin: 0; font-size: clamp(46px, 6vw, 70px); line-height: 1.02; letter-spacing: -.055em; }
.section-intro { max-width: 760px; margin: 21px 0 0; color: var(--muted); font-size: 18px; line-height: 1.58; }
.wide-intro { max-width: 910px; }

.tldr-section { background: white; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.tldr-section h2 { font-size: clamp(38px, 5vw, 60px); }
.lead { margin: 30px 0 0; color: #49586e; font-family: Georgia, "Times New Roman", serif; font-size: 22px; line-height: 1.55; }
.lead.secondary { margin-top: 15px; color: #6c7a8f; font-size: 19px; }

.story-card { margin-top: 42px; border: 1px solid var(--line); border-radius: 27px; overflow: hidden; background: white; box-shadow: 0 16px 48px rgba(50,71,101,.06); }
.story-stage { position: relative; min-height: 480px; display: grid; place-items: center; overflow: hidden; background: #fff9e9; }
.story-stage img { width: 100%; height: 100%; object-fit: contain; transition: opacity .16s ease, transform .16s ease; }
.story-stage img.is-changing { opacity: .25; transform: scale(.995); }
.story-missing { color: var(--muted); padding: 40px; text-align: center; }
.story-copy { display: grid; grid-template-columns: 320px 1fr; gap: 36px; padding: 27px 30px; border-top: 1px solid var(--line); }
.story-meta { display: flex; flex-direction: column; gap: 7px; }
.story-meta span:first-child { font: 700 10px ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: .15em; color: #8795a9; }
.story-meta span:last-child { font-weight: 820; }
.story-copy p { margin: 0; color: var(--muted); line-height: 1.55; }
.story-controls { display: flex; align-items: center; justify-content: center; gap: 13px; padding: 18px 24px 24px; }
.icon-button, .play-button, .copy-button { cursor: pointer; border: 1px solid #c9d4e0; background: white; color: var(--ink); transition: .15s ease; }
.icon-button { width: 42px; height: 42px; border-radius: 50%; font-size: 19px; }
.icon-button:hover, .play-button:hover, .copy-button:hover { border-color: #8d9caf; transform: translateY(-1px); }
.story-dots { display: flex; align-items: center; gap: 8px; padding: 0 7px; }
.story-dot { width: 9px; height: 9px; border: 0; border-radius: 50%; padding: 0; background: #cad4e0; cursor: pointer; }
.story-dot.active { width: 23px; border-radius: 999px; background: var(--blue); }
.play-button { padding: 10px 15px; border-radius: 999px; font-weight: 760; }
.play-symbol { display: inline-block; width: 18px; }
.analogy-bridge { display: grid; grid-template-columns: 1fr 70px 1fr; gap: 20px; align-items: center; margin-top: 24px; padding: 24px; border: 1px solid var(--line); border-radius: 20px; background: #eef3f8; }
.bridge-side { display: flex; flex-direction: column; gap: 8px; }
.bridge-side strong { font-size: 20px; }
.bridge-small { color: var(--muted); line-height: 1.45; }
.bridge-center { text-align: center; color: #9aa8b9; font-size: 32px; }

.animation-section { background: var(--dark); color: white; }
.animation-section h2 { max-width: 900px; }
.animation-intro { max-width: 850px; margin: 19px 0 0; color: #aeb9cb; font-size: 18px; line-height: 1.6; }
.video-shell { position: relative; margin-top: 38px; padding: 13px; border-radius: 27px; background: var(--dark-2); }
.video-shell video { display: block; width: 100%; aspect-ratio: 16/9; background: #05070b; border-radius: 17px; }
.video-placeholder { min-height: 470px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; border-radius: 17px; background: #0c1220; color: #dce4ef; text-align: center; padding: 30px; }
.video-placeholder span { color: #99a8bd; }
.video-placeholder code { color: white; }

.method-section { background: #f7f9fc; }
.method-story { display: grid; grid-template-columns: 1.18fr .82fr; gap: 44px; align-items: center; margin-top: 52px; padding: 28px; border: 1px solid var(--line); border-radius: 26px; background: white; box-shadow: 0 14px 40px rgba(50,71,101,.05); }
.method-story.reverse { grid-template-columns: .82fr 1.18fr; }
.method-story.reverse .method-figure-wrap { order: 2; }
.method-story.reverse .method-copy { order: 1; }
.method-figure-wrap { border-radius: 18px; overflow: hidden; background: #fff; border: 1px solid #e1e7ee; }
.method-figure-wrap img { width: 100%; height: auto; }
.spectral-wrap { padding: 8px; }
.method-copy { padding: 12px 10px; }
.method-copy h3 { margin: 11px 0 15px; font-size: clamp(28px, 3vw, 39px); line-height: 1.08; letter-spacing: -.035em; }
.method-copy p { margin: 0 0 13px; color: var(--muted); line-height: 1.62; font-size: 16px; }
.plain-takeaway { margin-top: 20px; padding: 14px 16px; border-left: 3px solid var(--blue); border-radius: 0 12px 12px 0; background: #eef7fc; color: #324358; font-weight: 720; line-height: 1.45; }
.reverse .plain-takeaway { border-left-color: var(--pink); background: #fff1f4; }
.method-story:last-child .plain-takeaway { border-left-color: #7d5bc7; background: #f5f1fc; }

.results-section { background: #eef3f8; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.result-cards { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 20px; margin-top: 40px; }
.result-card { position: relative; overflow: hidden; padding: 30px; min-height: 205px; background: white; border: 1px solid var(--line); border-radius: 24px; }
.result-card::after { content: ""; position: absolute; right: -45px; top: -55px; width: 160px; height: 160px; border-radius: 50%; opacity: .09; }
.blue-card::after { background: var(--blue); }
.red-card::after { background: var(--pink); }
.result-number { margin-top: 22px; font-size: 68px; line-height: .95; font-weight: 880; letter-spacing: -.065em; }
.blue-card .result-number { color: var(--blue-dark); }
.red-card .result-number { color: #d63a4d; }
.result-number span { font-size: 24px; color: #69768c; letter-spacing: -.02em; }
.result-card p { max-width: 460px; margin: 21px 0 0; color: var(--muted); line-height: 1.55; }
.paper-figure { margin: 38px 0 0; border: 1px solid var(--line); border-radius: 24px; overflow: hidden; background: white; }
.paper-figure img { width: 100%; padding: 18px; }
.paper-figure figcaption { padding: 14px 18px; border-top: 1px solid var(--line); color: #6e7e94; font-size: 13px; line-height: 1.5; }

.citation-section { background: white; }
.citation-heading { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.citation-heading h2 { font-size: 48px; }
.copy-button { border-radius: 999px; padding: 10px 18px; font-weight: 760; }
.bibtex { margin: 24px 0 0; padding: 28px; overflow-x: auto; border: 1px solid #ced8e3; border-radius: 18px; background: #f5f8fb; color: #273248; font: 14px/1.72 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace; }

.footer { padding: 31px 0; background: var(--dark); color: #c9d2e1; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.footer-inner > span { font-weight: 850; color: white; }
.footer-inner > div { display: flex; gap: 22px; font-size: 14px; }
.footer a:hover { color: white; }

@media (max-width: 900px) {
  .nav { display: none; }
  .rounding-card-head, .decision-row, .method-story, .method-story.reverse { grid-template-columns: 1fr; }
  .method-story.reverse .method-figure-wrap, .method-story.reverse .method-copy { order: initial; }
  .story-stage { min-height: 350px; }
  .story-copy { grid-template-columns: 1fr; gap: 14px; }
  .analogy-bridge { grid-template-columns: 1fr; }
  .bridge-center { transform: rotate(90deg); }
  .video-placeholder { min-height: 360px; }
  .scale-wrap { padding-left: 64px; padding-right: 64px; }
}

@media (max-width: 620px) {
  .shell { width: min(calc(100% - 28px), var(--max)); }
  .topbar { padding-inline: 15px; }
  .hero { padding-top: 65px; }
  .hero-subtitle br { display: none; }
  .authors { font-size: 16px; }
  .section { padding: 76px 0; }
  .rounding-card { padding: 20px; }
  .scale-wrap { padding: 68px 54px 92px; }
  .endpoint-group { width: 86px; }
  .endpoint-group-left { left: -43px; }
  .endpoint-group-right { right: -43px; }
  .endpoint-note { font-size: 11px; }
  .endpoint-note strong { font-size: 11px; }
  .scaled-dot { left: 48%; }
  .recon-dot, .recon-dot-label { left: 76%; }
  .scaled-dot-label { left: 48%; top: -56px; }
  .recon-dot-label { top: -73px; }
  .story-stage { min-height: 250px; }
  .story-controls { flex-wrap: wrap; }
  .result-cards { grid-template-columns: 1fr; }
  .result-number { font-size: 58px; }
  .method-story { padding: 17px; }
  .footer-inner { align-items: flex-start; }
  .footer-inner > div { flex-wrap: wrap; justify-content: flex-end; }
}

.rounding-head-right {
  max-width: 470px;
}

.rounding-head-right p {
  margin: 0;
}

.rounding-labels {
  display: flex;
  gap: 22px;
  margin-top: 12px;
  flex-wrap: wrap;
}

.rounding-labels span {
  font-size: 14px;
  color: var(--muted);
}

.rounding-labels strong {
  color: var(--ink);
}

.playback-tip {
  margin: 14px 4px 0;
  color: #aeb8ca;
  font-size: 14px;
  line-height: 1.5;
}

.playback-tip strong {
  color: #ffffff;
  font-weight: 700;
}