:root {
  --ink: #1b1b18;
  --paper: #f3f0e7;
  --paper-bright: #fbfaf5;
  --lime: #d9ff57;
  --yuel: #7b74c9;
  --rival: #57b98f;
  --rival2: #ef9450;
  --deep: #38356b;
  --line: rgba(27, 27, 24, .2);
  --line-soft: rgba(27, 27, 24, .1);
  --muted: #5f5d54;
  --shadow: 0 24px 70px rgba(27, 27, 24, .13);
  --mono: "DM Mono", ui-monospace, monospace;
  --sans: "Space Grotesk", system-ui, sans-serif;
  --serif: "Instrument Serif", Georgia, serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 90px; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: var(--sans); font-size: 16px; line-height: 1.68;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
img { display: block; max-width: 100%; height: auto; }
button, input { font: inherit; color: inherit; }
h1, h2, h3, h4 { font-weight: 500; }
em { font-family: var(--serif); font-style: italic; font-weight: 400; }

/* ---------- chrome ---------- */
.reading-progress { position: fixed; inset: 0 0 auto; z-index: 100; height: 3px; }
.reading-progress span { display: block; width: 0; height: 100%; background: var(--yuel); }

.topbar {
  position: sticky; top: 0; z-index: 50; height: 74px; padding: 0 clamp(18px, 4vw, 64px);
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  border-bottom: 1px solid var(--line); background: rgba(243,240,231,.9); backdrop-filter: blur(16px);
}
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; font: 500 11px/1 var(--mono); letter-spacing: .1em; }
.brand-mark {
  width: 40px; height: 40px; display: grid; place-items: center; border-radius: 50%;
  background: var(--ink); color: var(--lime); font-size: 11px; letter-spacing: .04em;
}
.topbar nav { display: flex; gap: 24px; }
.topbar nav a { text-decoration: none; font: 500 13px/1 var(--sans); }
.topbar nav a:hover { text-decoration: underline; text-underline-offset: 6px; }
.paper-link {
  padding: 10px 16px; border: 1px solid var(--ink); border-radius: 999px;
  text-decoration: none; font: 500 12px/1 var(--sans); white-space: nowrap;
}
.paper-link:hover { background: var(--lime); }
:focus-visible { outline: 3px solid var(--yuel); outline-offset: 3px; }
main { overflow-x: clip; }

/* ---------- shared type ---------- */
.eyebrow, .kicker { margin: 0 0 20px; font: 500 10px/1.6 var(--mono); letter-spacing: .14em; text-transform: uppercase; }
.eyebrow { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.eyebrow span { position: relative; }
.eyebrow span + span::before {
  content: ""; position: absolute; left: -10px; top: 50%; width: 3px; height: 3px; border-radius: 50%; background: currentColor;
}
.lead { max-width: 800px; margin: 30px 0 0; color: var(--muted); font-size: clamp(17px, 1.5vw, 21px); }

/* ---------- hero ---------- */
.hero {
  padding: clamp(56px, 7vw, 110px) clamp(18px, 5vw, 80px) clamp(40px, 5vw, 70px);
  background:
    linear-gradient(rgba(27,27,24,.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(27,27,24,.045) 1px, transparent 1px), var(--paper);
  background-size: 42px 42px;
}
.hero-grid {
  max-width: 1440px; margin: auto; display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, .9fr);
  align-items: center; gap: clamp(34px, 5vw, 84px);
}
.hero h1 { margin: 0; max-width: 900px; font: 400 clamp(42px, 5.8vw, 94px)/.98 var(--sans); letter-spacing: -.045em; }
.hero-deck { max-width: 700px; margin: 32px 0 0; color: var(--muted); font-size: clamp(16px, 1.4vw, 20px); }
.hero-deck strong { display: block; margin-top: 14px; color: var(--ink); font-weight: 500; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 16px; margin-top: 36px; font: 500 11px/1 var(--mono); letter-spacing: .06em; }
.primary-button, .ghost-button {
  display: inline-flex; align-items: center; gap: 26px; padding: 15px 20px; border-radius: 3px;
  text-decoration: none; font: 500 13px/1 var(--sans);
}
.primary-button { background: var(--ink); color: var(--paper); }
.primary-button span { color: var(--lime); }
.primary-button:hover { background: var(--deep); }
.ghost-button { border: 1px solid var(--ink); }
.ghost-button span { opacity: .55; }
.ghost-button:hover { background: var(--lime); }

.hero-stage { position: relative; }
.hero-stage svg { width: 100%; height: auto; overflow: visible; }
.stage-glow { animation: glowPulse 6s ease-in-out infinite; }
.hx-spokes line { stroke: rgba(27,27,24,.3); stroke-width: 1.6; stroke-dasharray: 5 6; animation: flow 3.2s linear infinite; }
.hx-spokes.ligand line { stroke: rgba(87,185,143,.55); animation-direction: reverse; }
.hx-protein circle { fill: var(--yuel); }
.hx-ligand circle { fill: var(--rival); }
.hx-joint circle { fill: var(--paper-bright); stroke: var(--ink); stroke-width: 2.5; }
.hx-joint text { fill: var(--ink); font: 500 10px var(--mono); letter-spacing: .08em; }
.stage-key { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 18px; font: 500 10px/1 var(--mono); letter-spacing: .08em; color: var(--muted); }
.stage-key span { display: inline-flex; align-items: center; gap: 7px; }
.stage-key i { display: block; width: 11px; height: 11px; border-radius: 50%; }
.k-protein { background: var(--yuel); }
.k-ligand { background: var(--rival); }
.k-joint { background: var(--paper-bright); border: 2px solid var(--ink); }

.hero-facts {
  max-width: 1440px; margin: clamp(46px, 6vw, 92px) auto 0;
  display: grid; grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
}
.hero-facts div { padding: 20px 22px 20px 0; border-right: 1px solid var(--line-soft); }
.hero-facts div:last-child { border-right: 0; }
.hero-facts div + div { padding-left: 22px; }
.hero-facts strong { display: block; font: 400 clamp(24px, 2.2vw, 34px)/1 var(--sans); letter-spacing: -.03em; }
.hero-facts span { display: block; margin-top: 8px; color: var(--muted); font-size: 12.5px; line-height: 1.4; }

/* ---------- chapters ---------- */
.chapter { position: relative; padding: clamp(84px, 11vw, 168px) clamp(18px, 7vw, 110px); }
.section-marker {
  position: absolute; top: 96px; left: clamp(18px, 2.6vw, 44px);
  display: flex; flex-direction: column; align-items: center; gap: 16px; font-family: var(--mono);
}
.section-marker span { width: 42px; height: 42px; display: grid; place-items: center; border: 1px solid currentColor; border-radius: 50%; font-size: 12px; }
.section-marker p { margin: 0; font-size: 9px; letter-spacing: .16em; writing-mode: vertical-rl; }
.chapter-copy, .chapter-heading { max-width: 1080px; margin: 0 auto 68px; }
.chapter-copy p:not(.kicker):not(.lead), .chapter-heading p:not(.kicker):not(.lead) { max-width: 740px; color: var(--muted); }
.chapter h2 { margin: 0; font: 400 clamp(32px, 4.7vw, 68px)/1.05 var(--sans); letter-spacing: -.045em; }
.chapter h3 { margin: 0 0 14px; font: 400 clamp(22px, 2.5vw, 36px)/1.18 var(--sans); letter-spacing: -.03em; }

/* ---------- thesis ---------- */
.thesis { max-width: 1240px; margin: clamp(60px, 8vw, 108px) auto 0; padding: clamp(28px, 5vw, 58px); background: var(--ink); color: var(--paper); }
.thesis > span { color: var(--lime); font: 500 10px/1 var(--mono); letter-spacing: .14em; }
.thesis blockquote { max-width: 960px; margin: 24px 0 44px; font: 400 clamp(23px, 3.2vw, 44px)/1.24 var(--sans); letter-spacing: -.035em; }
.thesis-split { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: rgba(243,240,231,.2); }
.thesis-split > div { padding: 28px; background: var(--ink); }
.thesis-tag { margin: 0 0 14px; font: 500 10px/1 var(--mono); letter-spacing: .12em; color: var(--lime); }
.thesis-split strong { display: block; font: 400 25px/1 var(--sans); letter-spacing: -.02em; }
.thesis-split p:not(.thesis-tag) { margin: 12px 0 0; color: rgba(243,240,231,.62); font-size: 14.5px; }

/* ---------- detail grid ---------- */
.detail-grid { max-width: 1240px; margin: clamp(50px, 7vw, 96px) auto 0; display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--line-soft); }
.detail-grid article { padding: 30px; border-right: 1px solid var(--line-soft); background: var(--paper-bright); }
.detail-grid article:last-child { border-right: 0; }
.detail-grid span { font: 500 9.5px/1 var(--mono); letter-spacing: .13em; color: var(--muted); }
.detail-grid h3 { margin: 24px 0 10px; font-size: 21px; }
.detail-grid p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* ---------- figures ---------- */
.paper-figure { max-width: 1240px; margin: clamp(50px, 7vw, 96px) auto 0; padding: 20px; background: var(--paper-bright); box-shadow: var(--shadow); }
.paper-figure.wide { max-width: 1380px; }
.figure-meta { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 14px; padding: 6px 4px 16px; font: 500 9.5px/1.4 var(--mono); letter-spacing: .11em; color: var(--muted); }
.paper-figure img { width: 100%; background: #fff; }
.figure-reading { display: grid; grid-template-columns: 230px 1fr; gap: 28px; padding: 26px 6px 6px; border-top: 1px solid var(--line-soft); }
.figure-reading h3 { margin: 0; font-size: 19px; }
.figure-reading p { margin: 0; color: var(--muted); font-size: 14.5px; }
.paper-figure details { margin-top: 18px; padding: 16px 6px 4px; border-top: 1px solid var(--line-soft); }
.paper-figure summary { cursor: pointer; font: 500 14px/1 var(--sans); }
.paper-figure details p { margin: 16px 0 0; color: var(--muted); font-size: 14.5px; }

/* ---------- narrative beats: prose beside one panel ---------- */
.beat {
  max-width: 1240px; margin: clamp(48px, 6.5vw, 90px) auto 0;
  display: grid; grid-template-columns: .8fr 1.2fr; gap: clamp(28px, 4vw, 60px); align-items: center;
}
.beat.reverse .beat-copy { order: 2; }
.beat-copy p:not(.kicker) { color: var(--muted); }
.beat-copy h3 { margin-bottom: 16px; }
.beat-figure { margin: 0; padding: 18px; background: var(--paper-bright); border: 1px solid var(--line-soft); box-shadow: var(--shadow); }
.beat-figure.narrow { max-width: 560px; justify-self: center; }
.beat-figure img { width: 100%; background: #fff; }
.beat-figure figcaption {
  margin-top: 16px; padding-top: 14px; border-top: 1px solid var(--line-soft);
  color: var(--muted); font-size: 13.5px; line-height: 1.62;
}
.beat-figure figcaption b { color: var(--ink); font-weight: 500; }
.fc-flag { display: block; margin-top: 10px; padding-left: 12px; border-left: 2px solid var(--yuel); font-size: 12.5px; }

/* ---------- figure captions on full-width figures ---------- */
.figure-caption { margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line-soft); }
.fc-lead { margin: 0 0 18px; font-size: 15px; }
.figure-panels { margin: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 12px 30px; }
.figure-panels > div { display: grid; grid-template-columns: 34px 1fr; gap: 12px; align-items: baseline; }
.figure-panels dt { font: 500 11px/1.5 var(--mono); color: var(--yuel); }
.figure-panels dd { margin: 0; color: var(--muted); font-size: 13.5px; line-height: 1.6; }
.fc-note { margin: 18px 0 0; padding-top: 14px; border-top: 1px solid var(--line-soft); color: var(--muted); font: 500 11px/1.6 var(--mono); }

/* ---------- DCA / DCC explainer ---------- */
.metric-note {
  max-width: 1240px; margin: clamp(56px, 7vw, 100px) auto 0;
  display: grid; grid-template-columns: 1.05fr .95fr; gap: clamp(28px, 4vw, 58px); align-items: center;
  padding: clamp(24px, 4vw, 44px); border: 1px solid var(--ink);
}
.metric-copy p:not(.kicker) { color: var(--muted); }
.metric-figure { position: relative; }
.metric-figure svg { width: 100%; height: auto; }
.mn-ligand line { stroke: var(--rival); stroke-width: 3; }
.mn-ligand circle { fill: var(--rival); }
.mn-centroid { fill: var(--paper-bright); stroke: var(--ink); stroke-width: 2.5; }
.mn-pred { fill: var(--rival2); }
.mn-lbl { fill: var(--muted); font: 500 10px var(--mono); letter-spacing: .07em; }
.mn-dca { fill: none; stroke: var(--rival2); stroke-width: 2.5; }
.mn-dcc { fill: none; stroke: var(--ink); stroke-width: 2.5; stroke-dasharray: 6 5; }
.mn-legend-lbl { fill: var(--muted); font: 500 10px var(--mono); letter-spacing: .05em; }
.mn-caption { display: block; margin-top: 8px; text-align: center; font: 500 9.5px/1 var(--mono); letter-spacing: .11em; color: var(--muted); }
.compare-readout { min-height: 52px; margin: 20px 0 0; padding-left: 16px; border-left: 3px solid var(--rival2); font-size: 15px; }

/* ---------- modes ---------- */
.modes-section { background: var(--ink); color: var(--paper); }
.modes-section .kicker, .modes-section .section-marker { color: var(--lime); }
.modes-section .lead, .modes-section .chapter-heading p:not(.kicker) { color: rgba(243,240,231,.66); }
.mode-lab { max-width: 1240px; margin: auto; border: 1px solid rgba(243,240,231,.2); }
.mode-switch { display: grid; grid-template-columns: 1fr 1fr; }
.mode-btn { padding: 20px; border: 0; border-right: 1px solid rgba(243,240,231,.2); border-bottom: 1px solid rgba(243,240,231,.2); background: transparent; color: rgba(243,240,231,.55); font-size: 15px; }
.mode-btn:last-child { border-right: 0; }
.mode-btn.active { background: var(--lime); color: var(--ink); border-bottom-color: var(--lime); }
.mode-body { display: grid; grid-template-columns: 1fr 1fr; }
.mode-copy { padding: clamp(24px, 3.5vw, 42px); border-right: 1px solid rgba(243,240,231,.2); }
.mode-copy h4 { margin: 0 0 16px; color: var(--paper); font: 400 clamp(21px, 2.2vw, 30px)/1.2 var(--sans); letter-spacing: -.025em; }
.mode-copy p { margin: 0 0 14px; color: rgba(243,240,231,.66); font-size: 15px; }
.mode-copy ul { margin: 18px 0 0; padding-left: 18px; }
.mode-copy li { margin-bottom: 9px; color: rgba(243,240,231,.66); font-size: 14.5px; }
.mode-stage { position: relative; min-height: 340px; background: #fff; }
.mode-stage img { position: absolute; inset: 16px; margin: auto; width: calc(100% - 32px); height: calc(100% - 56px); object-fit: contain; opacity: 0; transition: opacity .4s ease; }
.mode-stage img.active { opacity: 1; }
.mode-caption { position: absolute; left: 0; right: 0; bottom: 14px; text-align: center; font: 500 10px/1.5 var(--mono); letter-spacing: .1em; color: var(--muted); }

.craft-note {
  max-width: 1240px; margin: clamp(50px, 7vw, 96px) auto 0;
  display: grid; grid-template-columns: 220px 1fr; gap: 30px;
  padding: clamp(24px, 3.5vw, 40px); border: 1px solid rgba(243,240,231,.25);
}
.craft-note > span { font: 500 10px/1.7 var(--mono); letter-spacing: .12em; color: var(--lime); }
.craft-note h3 { color: var(--paper); }
.craft-note p { color: rgba(243,240,231,.62); }
.craft-note p:last-child { margin-bottom: 0; }

/* ---------- compare ---------- */
.compare-lab, .probe-lab {
  max-width: 1240px; margin: clamp(50px, 7vw, 96px) auto 0;
  display: grid; grid-template-columns: .9fr 1.1fr; gap: clamp(28px, 4vw, 56px); align-items: center;
}
.compare-copy p:not(.kicker), .probe-copy p:not(.kicker):not(.probe-readout) { color: var(--muted); }
.compare-grid-toggle { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.compare-btn { padding: 10px 15px; border-radius: 999px; }
.compare-btn.active { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.compare-grid-toggle.small .compare-btn { padding: 8px 13px; font-size: 12px; }
.compare-stage { position: relative; min-height: 380px; padding: 16px; background: #fff; border: 1px solid var(--line-soft); }
.compare-stage.inline { min-height: 320px; }
.compare-stage img { position: absolute; inset: 16px; margin: auto; width: calc(100% - 32px); height: calc(100% - 32px); object-fit: contain; opacity: 0; transition: opacity .4s ease; }
.compare-stage img.active { opacity: 1; }
.probe-readout { min-height: 52px; margin: 20px 0 0; padding-left: 16px; border-left: 3px solid var(--rival2); font-size: 15px; }
.stage-note { margin: 12px 0 0; font: 500 10px/1.5 var(--mono); letter-spacing: .09em; color: var(--muted); }

.af-robust { max-width: 1240px; margin: clamp(50px, 7vw, 96px) auto 0; display: grid; grid-template-columns: 1.05fr .95fr; gap: clamp(28px, 4vw, 56px); align-items: center; }
.af-robust-copy p:not(.kicker) { color: var(--muted); }

/* ---------- edges ---------- */
.edges-section { background: #101010; color: var(--paper); }
.edges-section .kicker, .edges-section .section-marker { color: var(--yuel); }
.edges-section .lead { color: rgba(243,240,231,.6); }
.limit-list { max-width: 1080px; margin: auto; }
.limit-list article { display: grid; grid-template-columns: 62px 1fr; gap: 22px; padding: 30px 0; border-top: 1px solid rgba(243,240,231,.16); }
.limit-list article > span { font: 500 12px/1.6 var(--mono); color: var(--yuel); }
.limit-list h3 { margin: 0 0 10px; font-size: 21px; }
.limit-list p { margin: 0; color: rgba(243,240,231,.58); font-size: 15px; }

/* ---------- takeaway + sources ---------- */
.takeaway { padding: clamp(80px, 12vw, 168px) clamp(18px, 8vw, 130px); background: var(--lime); }
.takeaway h2 { max-width: 1150px; margin: 0; font: 400 clamp(28px, 4.3vw, 62px)/1.1 var(--sans); letter-spacing: -.045em; }
.takeaway-flow { display: flex; align-items: center; flex-wrap: wrap; gap: 14px; margin: 54px 0 40px; }
.takeaway-flow span { padding: 13px 18px; border: 1px solid var(--ink); border-radius: 999px; font-size: 14px; }
.takeaway-flow i { font-style: normal; font-size: 20px; opacity: .5; }
.takeaway > p:last-child { max-width: 920px; margin: 0; font-size: clamp(16px, 1.4vw, 19px); }

.sources { padding: clamp(70px, 9vw, 128px) clamp(18px, 8vw, 130px); }
.sources-intro { max-width: 1240px; margin: 0 auto 48px; display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1fr); gap: clamp(24px, 5vw, 70px); align-items: end; }
.sources h2 { margin: 0; font: 400 clamp(32px, 4.2vw, 58px)/1.02 var(--sans); letter-spacing: -.04em; }
.sources-note { max-width: 520px; margin: 0; color: var(--muted); font-size: 14.5px; }
.paper-cards { max-width: 1240px; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.paper-cards.single { grid-template-columns: minmax(0, 760px); }
.paper-card { display: flex; flex-direction: column; padding: clamp(24px, 3vw, 36px); background: var(--paper-bright); border: 1px solid var(--line); box-shadow: var(--shadow); }
.paper-card-head { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; margin-bottom: 26px; font: 500 9.5px/1 var(--mono); letter-spacing: .12em; }
.paper-badge { padding: 6px 10px; border-radius: 999px; background: var(--ink); color: var(--lime); }
.paper-pages { color: var(--muted); }
.paper-card h3 { margin: 0 0 16px; font: 400 clamp(20px, 1.9vw, 26px)/1.24 var(--sans); letter-spacing: -.025em; }
.paper-authors { margin: 0 0 6px; font-size: 14px; }
.paper-meta { margin: 0 0 28px; color: var(--muted); font: 500 11.5px/1.6 var(--mono); }
.paper-actions { display: flex; flex-wrap: wrap; gap: 9px; margin-top: auto; }
.paper-btn { display: inline-flex; align-items: center; gap: 10px; padding: 11px 16px; border: 1px solid var(--line); border-radius: 999px; text-decoration: none; font: 500 12.5px/1 var(--sans); }
.paper-btn span { opacity: .55; }
.paper-btn:hover { border-color: var(--ink); background: rgba(27,27,24,.05); }
.paper-btn.primary { border-color: var(--ink); background: var(--ink); color: var(--paper); }
.paper-btn.primary span { color: var(--lime); opacity: 1; }
.paper-btn.primary:hover { background: var(--deep); border-color: var(--deep); }
.source-links { max-width: 1240px; margin: 48px auto 0; border-top: 1px solid var(--line); }
.source-links a { display: grid; grid-template-columns: 46px 1.15fr .85fr; gap: 20px; align-items: baseline; padding: 22px 0; border-bottom: 1px solid var(--line); text-decoration: none; }
.source-links a:hover strong { text-decoration: underline; text-underline-offset: 5px; }
.source-links span, .source-links small { color: var(--muted); font: 500 11px/1.5 var(--mono); }
.source-links strong { font-weight: 500; font-size: 16px; }

.colophon { padding: 0 clamp(18px, 8vw, 130px) clamp(50px, 7vw, 90px); }
.colophon > div { max-width: 920px; padding-top: 34px; border-top: 1px solid var(--line); }
.colophon p { margin: 0; color: var(--muted); font-size: 13.5px; }

footer { padding: 26px clamp(18px, 5vw, 70px); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; border-top: 1px solid var(--line); font: 500 9.5px/1.6 var(--mono); letter-spacing: .1em; }
footer p { margin: 0; }
footer a { text-decoration: none; }
footer a:hover { text-decoration: underline; text-underline-offset: 5px; }

/* ---------- motion ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: none; }
@keyframes glowPulse { 50% { opacity: .5; } }
@keyframes flow { to { stroke-dashoffset: -22; } }

/* ---------- responsive ---------- */
@media (max-width: 1020px) {
  .topbar nav { display: none; }
  .hero-grid, .cascade-lab, .af-split, .gen-body, .complexity-lab, .mode-body,
  .compare-lab, .probe-lab, .af-robust, .surprise-body, .sources-intro, .paper-cards,
  .beat, .metric-note, .figure-panels { grid-template-columns: 1fr; }
  .beat.reverse .beat-copy { order: 0; }
  .paper-cards.single { grid-template-columns: 1fr; }
  .hero-grid { gap: 52px; }
  .hero-stage { max-width: 460px; margin: auto; }
  .section-marker { position: static; flex-direction: row; align-items: center; margin-bottom: 40px; }
  .section-marker p { writing-mode: initial; }
  .thesis-split, .gen-tabs, .detail-grid { grid-template-columns: 1fr; }
  .gen-tab, .detail-grid article { border-right: 0; border-bottom: 1px solid var(--line); }
  .gen-tab:last-child, .detail-grid article:last-child { border-bottom: 0; }
  .gen-visual { border-right: 0; border-bottom: 1px solid var(--line); }
  .mode-copy { border-right: 0; border-bottom: 1px solid rgba(243,240,231,.2); }
  .figure-reading, .craft-note { grid-template-columns: 1fr; }
  .sources-intro { align-items: start; }
}

@media (max-width: 720px) {
  html { scroll-padding-top: 74px; }
  .topbar { height: 64px; padding: 0 14px; }
  .brand > span:last-child { display: none; }
  .paper-link { padding: 8px 12px; font-size: 11px; }
  .hero { padding-inline: 16px; }
  .hero-facts, .cost-stats, .result-stats, .surprise-stats { grid-template-columns: 1fr; }
  .hero-facts div, .hero-facts div + div { padding: 16px 0; border-right: 0; border-bottom: 1px solid var(--line-soft); }
  .hero-facts div:last-child { border-bottom: 0; }
  .chapter { padding-inline: 16px; }
  .mode-switch { grid-template-columns: 1fr; }
  .mode-btn { border-right: 0; }
  .compare-stage, .mode-stage { min-height: 280px; }
  .source-links a { grid-template-columns: 34px 1fr; }
  .source-links small { grid-column: 2; }
  .takeaway, .sources, .colophon { padding-inline: 16px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ================= components specific to this page ================= */

/* ---------- hero stage: a pocket that opens ---------- */
.hero-stage svg { width: 100%; height: auto; overflow: visible; }
.hs-body { fill: rgba(27,27,24,.05); stroke: var(--ink); stroke-width: 2.5; }
.hs-cavity { fill: var(--paper-bright); stroke: var(--line); stroke-width: 1.5; stroke-dasharray: 6 7; }
.hs-ligand line { stroke: var(--yuel); stroke-width: 4; }
.hs-ligand circle { fill: var(--yuel); }
.hs-ligand { opacity: .25; transition: opacity .6s ease, transform .8s cubic-bezier(.4,0,.2,1); transform-origin: 260px 230px; transform: translateY(84px) scale(.82); }
.hs-ligand.seated { opacity: 1; transform: none; }
.hs-arm line { stroke: var(--ink); stroke-width: 4; stroke-linecap: round; }
.hs-arm circle { fill: var(--paper-bright); stroke: var(--ink); stroke-width: 3; }
.hs-arm { transition: transform .8s cubic-bezier(.4,0,.2,1); transform-origin: 260px 214px; }
.hs-arm.open.left { transform: rotate(-32deg); }
.hs-arm.open.right { transform: rotate(32deg); }
.hs-bridge { stroke: var(--rival2); stroke-width: 4; stroke-dasharray: 6 6; transition: opacity .5s ease; }
.hs-bridge.broken { opacity: 0; }
.hs-label { fill: var(--muted); font: 500 11px var(--mono); letter-spacing: .1em; }
.stage-controls { display: flex; gap: 9px; margin-top: 16px; }
.hs-btn { padding: 10px 16px; border: 1px solid var(--line); border-radius: 999px; background: transparent; cursor: pointer; font: 500 12.5px/1 var(--sans); }
.hs-btn.active { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.stage-readout { min-height: 52px; margin: 14px 0 0; padding-left: 14px; border-left: 3px solid var(--yuel); font-size: 14.5px; }

/* ---------- family tree ---------- */
.tree-lab {
  max-width: 1240px; margin: 0 auto; display: grid; grid-template-columns: .92fr 1.08fr;
  gap: clamp(28px, 4vw, 58px); align-items: center;
  padding: clamp(24px, 4vw, 46px); border: 1px solid var(--line-soft); background: var(--paper-bright);
}
.tree-copy p:not(.kicker):not(.tree-readout) { color: var(--muted); }
.tree-controls { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 24px; }
.tree-btn { padding: 10px 16px; border: 1px solid var(--line); border-radius: 999px; background: transparent; cursor: pointer; font: 500 12.5px/1 var(--sans); }
.tree-btn.active { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.tree-readout { min-height: 62px; margin: 20px 0 0; padding-left: 16px; border-left: 3px solid var(--yuel); font-size: 15px; }
.tree-demo svg { width: 100%; height: auto; background: var(--paper); border: 1px solid var(--line-soft); }
.tr-layer { opacity: 0; transition: opacity .4s ease; }
.tr-layer.on { opacity: 1; }
.tr-head { fill: var(--ink); font: 500 11px var(--mono); letter-spacing: .12em; }
.tr-note { fill: var(--muted); font: 500 10.5px var(--mono); letter-spacing: .05em; }
.tr-smiles { fill: var(--yuel); font: 500 15px var(--mono); letter-spacing: .04em; }
.tr-graph line { stroke: var(--yuel); stroke-width: 3; }
.tr-graph circle { fill: var(--yuel); }
.tr-wall { fill: none; stroke-width: 4; stroke-linecap: round; }
.tr-wall.rigid { stroke: var(--ink); }
.tr-wall.live { stroke: var(--rival); stroke-dasharray: 10 7; }
.tr-lock text { fill: var(--muted); font: 500 11px var(--mono); letter-spacing: .16em; }
.tr-sidechains line { stroke: var(--rival); stroke-width: 3; stroke-linecap: round; }
.tr-sidechains circle { fill: var(--rival); }

/* ---------- atom-count scale ---------- */
.scale-block {
  max-width: 1240px; margin: clamp(56px, 7vw, 100px) auto 0; padding: clamp(22px, 3vw, 36px);
  background: var(--paper-bright); border: 1px solid var(--line-soft); box-shadow: var(--shadow);
}
.scale-head { padding-bottom: 22px; border-bottom: 1px solid var(--line-soft); }
.scale-head .kicker { margin-bottom: 10px; }
.scale-head h3 { margin: 0; }
.scale-body { padding-top: 26px; display: grid; grid-template-columns: 1fr 1fr; gap: clamp(24px, 4vw, 50px); align-items: center; }
.scale-bars { display: grid; gap: 22px; }
.sb-row { display: grid; grid-template-columns: 1fr; gap: 8px; }
.sb-row span { font: 500 11px/1 var(--mono); letter-spacing: .07em; }
.sb-row b { font: 500 13px/1 var(--mono); }
.sb-track { height: 22px; background: rgba(27,27,24,.07); border-radius: 3px; overflow: hidden; }
.sb-track i { display: block; width: var(--w); height: 100%; border-radius: 3px; }
.sb-track i.lig { background: var(--yuel); }
.sb-track i.both { background: var(--deep); }
.scale-note { margin: 0; color: var(--muted); font-size: 14.5px; }

/* ---------- dual diffusion ---------- */
.dual-lab {
  max-width: 1240px; margin: clamp(56px, 7vw, 100px) auto 0; display: grid;
  grid-template-columns: .95fr 1.05fr; gap: clamp(28px, 4vw, 56px); align-items: center;
  padding: clamp(24px, 4vw, 44px); border: 1px solid var(--line);
}
.dual-copy p:not(.kicker):not(.dual-readout) { color: var(--muted); }
.dual-slider { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 8px 14px; margin-top: 26px; }
.dual-slider span { font: 500 11px/1 var(--mono); letter-spacing: .07em; }
.dual-slider output { font: 500 14px/1 var(--mono); }
.dual-slider input { grid-column: span 2; width: 100%; accent-color: var(--yuel); }
.dual-readout { min-height: 54px; margin: 18px 0 0; padding-left: 16px; border-left: 3px solid var(--yuel); font-size: 15px; }
.dual-demo { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.dual-panel { padding: 14px; background: var(--paper-bright); border: 1px solid var(--line-soft); text-align: center; }
.dual-panel svg { width: 100%; height: auto; }
.dual-head { display: block; font: 500 9.5px/1 var(--mono); letter-spacing: .12em; color: var(--muted); }
.dual-panel em { display: block; margin-top: 10px; font-style: normal; font: 500 10px/1.5 var(--mono); color: var(--muted); }
.dd-atom { stroke: var(--ink); stroke-width: 1.2; }
.dd-bond { stroke: rgba(27,27,24,.3); stroke-width: 2; }

/* ---------- denoising scrubber ---------- */
.scrub-lab {
  max-width: 1240px; margin: 0 auto; display: grid; grid-template-columns: .9fr 1.1fr;
  gap: clamp(28px, 4vw, 56px); align-items: center;
}
.scrub-copy p:not(.kicker):not(.scrub-readout) { color: var(--muted); }
.scrub-steps { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.scrub-btn { padding: 10px 15px; border: 1px solid var(--line); border-radius: 999px; background: transparent; cursor: pointer; font: 500 11.5px/1 var(--mono); }
.scrub-btn.active { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.scrub-readout { min-height: 54px; margin: 20px 0 0; padding-left: 16px; border-left: 3px solid var(--rival2); font-size: 15px; }
.scrub-demo { position: relative; min-height: 420px; padding: 16px; background: #fff; border: 1px solid var(--line-soft); }
.scrub-demo img { position: absolute; inset: 16px; margin: auto; width: calc(100% - 32px); height: calc(100% - 32px); object-fit: contain; opacity: 0; transition: opacity .4s ease; }
.scrub-demo img.active { opacity: 1; }

.compare-stage.tall { min-height: 640px; }

@media (max-width: 1020px) {
  .tree-lab, .dual-lab, .scrub-lab, .scale-body { grid-template-columns: 1fr; }
  .hero-stage { max-width: 460px; margin: auto; }
  .compare-stage.tall { min-height: 520px; }
}
@media (max-width: 720px) {
  .dual-demo { grid-template-columns: 1fr; }
  .scrub-demo { min-height: 340px; }
  .compare-stage.tall { min-height: 420px; }
}