:root {
  --ink: #17212b;
  --ink-2: #34414e;
  --muted: #5e6871;
  --paper: #f3f0e9;
  --paper-2: #e9e4da;
  --white: #fffdf7;
  --navy: #101d2c;
  --navy-2: #162a3e;
  --red: #e75f43;
  --red-deep: #bf422e;
  --blue: #76a8c9;
  --gold: #d7a94d;
  --green: #6aa587;
  --line: rgba(23, 33, 43, .16);
  --serif: "Newsreader", Georgia, serif;
  --sans: "Manrope", system-ui, sans-serif;
  --mono: "DM Mono", monospace;
  --content: min(1180px, calc(100vw - 48px));
  --shadow: 0 22px 60px rgba(18, 28, 37, .12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  opacity: .19;
  pointer-events: none;
  z-index: 10;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.95' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.12'/%3E%3C/svg%3E");
}

a { color: inherit; }
button, input, select { font: inherit; }
button { color: inherit; }
button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 2px solid white;
  outline-offset: 2px;
  box-shadow: 0 0 0 5px var(--ink);
}
canvas, svg { display: block; max-width: 100%; }
h1, h2, h3, h4, p { margin-top: 0; }
h1, h2, h3 { text-wrap: balance; }
h1, h2 {
  font-family: var(--serif);
  font-weight: 600;
  letter-spacing: -.035em;
  line-height: .98;
}
h2 { font-size: clamp(3rem, 6vw, 5.8rem); }
h3 { line-height: 1.18; }

.skip-link {
  position: fixed;
  left: 12px;
  top: -80px;
  z-index: 100;
  padding: 12px 18px;
  background: var(--white);
  color: var(--ink);
  transition: top .2s;
}
.skip-link:focus { top: 12px; }
.reading-progress {
  position: fixed;
  z-index: 70;
  top: 0;
  left: 0;
  height: 3px;
  width: 100%;
}
.reading-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--red);
}

.site-header {
  position: absolute;
  z-index: 40;
  top: 0;
  left: 50%;
  width: var(--content);
  transform: translateX(-50%);
  height: 94px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--white);
  border-bottom: 1px solid rgba(255,255,255,.18);
}
.brand {
  display: flex;
  gap: 13px;
  align-items: center;
  text-decoration: none;
}
.brand-mark {
  width: 39px;
  height: 39px;
  border: 1px solid rgba(255,255,255,.45);
  border-radius: 50%;
  position: relative;
}
.brand-mark span {
  position: absolute;
  border: 1px solid var(--red);
  border-radius: 50%;
  width: 7px;
  height: 7px;
}
.brand-mark span:nth-child(1) { left: 8px; top: 16px; }
.brand-mark span:nth-child(2) { left: 20px; top: 9px; }
.brand-mark span:nth-child(3) { left: 22px; top: 24px; }
.brand small {
  display: block;
  color: rgba(255,255,255,.6);
  font: 400 9px/1.2 var(--mono);
  letter-spacing: .14em;
}
.brand strong { font-size: 14px; font-weight: 600; }
.top-nav { display: flex; gap: 29px; align-items: center; }
.top-nav a {
  font-size: 12px;
  text-decoration: none;
  color: rgba(255,255,255,.76);
}
.top-nav a:hover { color: var(--white); }
.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 0;
  background: transparent;
}
.nav-toggle span { display: block; height: 1px; width: 22px; margin: 6px auto; background: white; }

.chapter-rail {
  position: fixed;
  z-index: 35;
  top: 50%;
  left: 18px;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 4px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity .3s;
}
.chapter-rail.visible { opacity: 1; visibility: visible; pointer-events: auto; }
.chapter-rail p {
  margin: 0 0 8px 29px;
  color: var(--muted);
  text-transform: uppercase;
  font: 500 8px/1 var(--mono);
  letter-spacing: .14em;
}
.chapter-rail a {
  display: flex;
  gap: 10px;
  align-items: center;
  width: 34px;
  height: 25px;
  overflow: hidden;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  font-size: 10px;
  transition: width .25s, color .25s;
}
.chapter-rail a span {
  flex: 0 0 25px;
  height: 25px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  font: 8px/1 var(--mono);
  background: rgba(243,240,233,.9);
  backdrop-filter: blur(8px);
}
.chapter-rail a:hover,
.chapter-rail a:focus-visible,
.chapter-rail a.active { width: 130px; color: var(--ink); }
.chapter-rail a.active span { background: var(--red-deep); border-color: var(--red-deep); color: white; }
.motion-toggle {
  position: fixed;
  z-index: 65;
  right: 18px;
  bottom: 18px;
  min-height: 44px;
  padding: 10px 14px;
  border: 1px solid rgba(255,255,255,.35);
  color: white;
  background: rgba(16,29,44,.94);
  box-shadow: var(--shadow);
  cursor: pointer;
  font: 500 10px/1 var(--mono);
  text-transform: uppercase;
  letter-spacing: .05em;
}
.motion-toggle span { margin-right: 6px; color: var(--red); }

.hero {
  min-height: 900px;
  color: var(--white);
  background:
    radial-gradient(circle at 86% 24%, rgba(118,168,201,.15), transparent 28%),
    radial-gradient(circle at 35% 80%, rgba(231,95,67,.1), transparent 32%),
    var(--navy);
  overflow: hidden;
  position: relative;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(255,255,255,.024) 1px, transparent 1px), linear-gradient(90deg,rgba(255,255,255,.024) 1px, transparent 1px);
  background-size: 54px 54px;
  mask-image: linear-gradient(to bottom, black, transparent 90%);
  pointer-events: none;
}
.hero-grid {
  width: var(--content);
  min-height: 800px;
  margin: 0 auto;
  padding-top: 145px;
  display: grid;
  grid-template-columns: .92fr 1.08fr;
  gap: 30px;
  align-items: center;
  position: relative;
  z-index: 2;
}
.hero-copy { padding-bottom: 70px; }
.eyebrow {
  margin-bottom: 20px;
  color: var(--red-deep);
  font: 500 10px/1.2 var(--mono);
  letter-spacing: .17em;
  text-transform: uppercase;
}
.eyebrow.light { color: var(--red); }
.hero h1 {
  max-width: 710px;
  margin-bottom: 26px;
  font-size: clamp(4.6rem, 7.8vw, 8rem);
  line-height: .88;
}
.hero-deck {
  max-width: 600px;
  color: rgba(255,255,255,.7);
  font-size: 18px;
  line-height: 1.6;
}
.hero-actions { display: flex; gap: 12px; margin: 36px 0 46px; }
.button {
  display: inline-flex;
  min-height: 50px;
  padding: 0 21px;
  gap: 28px;
  align-items: center;
  border: 1px solid rgba(255,255,255,.25);
  text-decoration: none;
  text-transform: uppercase;
  font: 500 10px/1 var(--mono);
  letter-spacing: .1em;
}
.button.primary { border-color: var(--red-deep); background: var(--red-deep); color: white; }
.button:hover { filter: brightness(1.08); }
.hero-meta {
  display: flex;
  gap: 25px;
  color: rgba(255,255,255,.48);
  font: 400 9px/1.5 var(--mono);
}
.hero-meta b { display: block; color: rgba(255,255,255,.8); font-weight: 400; text-transform: uppercase; }
.hero-visual {
  position: relative;
  min-height: 620px;
}
.hero-visual canvas {
  width: 100%;
  height: 620px;
  border-radius: 50% 50% 46% 54% / 55% 46% 54% 45%;
}
.hero-equation {
  position: absolute;
  padding: 8px 12px;
  color: rgba(255,255,255,.7);
  border: 1px solid rgba(255,255,255,.12);
  background: rgba(16,29,44,.7);
  backdrop-filter: blur(9px);
  font: 11px/1 var(--mono);
}
.eq-a { top: 17%; left: 3%; }
.eq-b { top: 62%; right: -2%; }
.eq-c { top: 42%; left: 14%; }
.visual-caption {
  position: absolute;
  bottom: 20px;
  right: 10px;
  color: rgba(255,255,255,.5);
  font: 9px/1.4 var(--mono);
}
.pulse-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 7px;
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 0 0 0 rgba(231,95,67,.5);
  animation: pulse 2s infinite;
}
@keyframes pulse { 70% { box-shadow: 0 0 0 9px rgba(231,95,67,0); } }
.hero-foot {
  position: relative;
  z-index: 3;
  width: var(--content);
  min-height: 100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 2fr 1fr;
  gap: 30px;
  align-items: center;
  border-top: 1px solid rgba(255,255,255,.15);
  color: rgba(255,255,255,.54);
  font: 9px/1 var(--mono);
  text-transform: uppercase;
  letter-spacing: .12em;
}
.hero-foot p:last-child { text-align: right; }
.scale-word { display: flex; align-items: center; justify-content: center; gap: 10px; }
.scale-word i { display: block; width: 60px; height: 1px; background: rgba(255,255,255,.25); }

.page-section { width: var(--content); margin: 0 auto; }
.orientation { padding: 74px 0; border-bottom: 1px solid var(--line); }
.orientation-grid { display: grid; grid-template-columns: 1fr 1.35fr; gap: 90px; }
.orientation h2 { max-width: 550px; font-size: clamp(2.4rem, 4vw, 4.2rem); }
.orientation-copy > p { max-width: 670px; font-size: 15px; color: var(--ink-2); }
.legend { display: flex; flex-wrap: wrap; gap: 22px; margin-top: 28px; color: var(--muted); font: 9px/1 var(--mono); text-transform: uppercase; letter-spacing: .07em; }
.level { display: inline-block; width: 9px; height: 9px; border-radius: 50%; }
.level.intuition { background: var(--blue); }
.level.derivation { background: var(--gold); }
.level.research { background: var(--red); }

#big-picture, #hard-spheres, #boltzmann, #proof, #lineage, #check { padding-top: 140px; padding-bottom: 140px; }
.section-heading { margin-bottom: 60px; }
.section-heading h2 { max-width: 900px; margin-bottom: 24px; }
.section-heading .lede, .lede { max-width: 650px; color: var(--muted); font-size: 16px; }
.split-heading { display: grid; grid-template-columns: 1.35fr .65fr; gap: 80px; align-items: end; }
.split-heading .lede { padding-bottom: 12px; }

.interactive-card {
  border: 1px solid var(--line);
  background: rgba(255,253,247,.76);
  box-shadow: var(--shadow);
}
.scale-lab { overflow: hidden; }
.lab-toolbar { display: grid; grid-template-columns: repeat(3, 1fr); border-bottom: 1px solid var(--line); }
.scale-tab {
  min-height: 92px;
  padding: 20px 28px;
  border: 0;
  border-right: 1px solid var(--line);
  background: transparent;
  text-align: left;
  cursor: pointer;
  font: 600 14px/1.2 var(--sans);
}
.scale-tab:last-child { border-right: 0; }
.scale-tab span { display: block; margin-bottom: 8px; color: var(--muted); font: 9px/1 var(--mono); }
.scale-tab.active { background: var(--ink); color: white; }
.scale-tab.active span { color: var(--red); }
.scale-stage { min-height: 520px; position: relative; overflow: hidden; background: #d9dfdd; }
.scale-stage canvas { width: 100%; height: 520px; }
.scale-overlay {
  position: absolute;
  left: 30px;
  bottom: 27px;
  padding: 14px 18px;
  border-left: 3px solid var(--red);
  background: rgba(255,253,247,.9);
  backdrop-filter: blur(8px);
}
.scale-overlay p { margin: 0; color: var(--muted); font: 9px/1.2 var(--mono); }
.scale-overlay strong { font: 500 13px/1.7 var(--mono); }
.scale-explanation { display: grid; grid-template-columns: 2fr 1fr 1fr; }
.scale-explanation > div { padding: 30px; border-right: 1px solid var(--line); }
.scale-explanation > div:last-child { border-right: 0; }
.scale-explanation h3 { margin-bottom: 8px; font: 600 20px/1.25 var(--serif); }
.scale-explanation p { margin: 0; color: var(--muted); font-size: 13px; }
.step-index, .def-label {
  display: block;
  margin-bottom: 12px;
  color: var(--red-deep);
  font: 500 9px/1 var(--mono);
  letter-spacing: .1em;
}

.pipeline { display: grid; grid-template-columns: 1fr .55fr 1fr .55fr 1fr; gap: 14px; margin: 70px 0; align-items: stretch; }
.pipeline article { min-height: 285px; padding: 27px; border: 1px solid var(--line); background: var(--paper-2); position: relative; }
.pipeline-num { position: absolute; top: 18px; right: 20px; color: var(--muted); font: 10px/1 var(--mono); }
.pipeline-icon { height: 76px; margin: 25px 0 25px; position: relative; }
.particles-icon i { position: absolute; width: 16px; height: 16px; border: 1.5px solid var(--red); border-radius: 50%; }
.particles-icon i:nth-child(1) { left: 7px; top: 11px; }.particles-icon i:nth-child(2) { left: 50px; top: 42px; }
.particles-icon i:nth-child(3) { left: 88px; top: 13px; }.particles-icon i:nth-child(4) { left: 121px; top: 51px; }
.distribution-icon i {
  position: absolute; inset: 0; border-radius: 50%;
  background: radial-gradient(circle at 52% 46%, var(--red), rgba(231,95,67,.2) 20%, transparent 52%), radial-gradient(circle at 35% 55%, rgba(118,168,201,.8), transparent 35%);
  filter: blur(5px);
}
.flow-icon i { position: absolute; left: 0; width: 145px; height: 20px; border-top: 1px solid var(--blue); border-radius: 50%; }
.flow-icon i:nth-child(1) { top: 7px; }.flow-icon i:nth-child(2) { top: 31px; left: 20px; }.flow-icon i:nth-child(3) { top: 55px; left: 4px; }
.pipeline article > p { color: var(--red-deep); font: 9px/1 var(--mono); text-transform: uppercase; }
.pipeline article h3 { margin: 12px 0; font: 600 23px/1.08 var(--serif); }
.pipeline article code { color: var(--muted); font: 10px/1.5 var(--mono); }
.pipeline-arrow { display: flex; flex-direction: column; justify-content: center; text-align: center; }
.pipeline-arrow b { font-size: 10px; }
.pipeline-arrow span { color: var(--muted); font: 8px/1.4 var(--mono); }
.pipeline-arrow svg { width: 100%; margin: 15px 0; fill: none; stroke: var(--ink); stroke-width: 1; }
.pipeline-arrow em { color: var(--muted); font: 400 8px/1.4 var(--mono); }
.pipeline-arrow .gap.closed { color: var(--red-deep); }

.concept-callout { display: flex; gap: 25px; padding: 30px 34px; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.callout-mark { flex: 0 0 30px; width: 30px; height: 30px; display: grid; place-items: center; border: 1px solid var(--red); border-radius: 50%; color: var(--red-deep); font: 500 12px/1 var(--mono); }
.concept-callout h3 { margin-bottom: 7px; font: 600 22px/1.2 var(--serif); }
.concept-callout p { margin: 0; color: var(--muted); font-size: 14px; }
.concept-callout.inverse { border-color: rgba(255,255,255,.28); }
.concept-callout.inverse h3 { color: white; }.concept-callout.inverse p { color: rgba(255,255,255,.6); }

.award-band { padding: 115px 0 70px; background: #8f2f28; color: white; }
.award-inner { display: grid; grid-template-columns: 210px 1fr; gap: 70px; align-items: center; }
.award-seal { width: 180px; height: 180px; position: relative; display: grid; place-items: center; }
.award-seal svg { position: absolute; inset: 0; fill: none; stroke: rgba(255,255,255,.5); stroke-width: 1; }
.award-seal svg path { fill: rgba(255,255,255,.12); }
.award-seal span { font: 500 13px/1 var(--mono); }
.award-copy blockquote { max-width: 890px; margin: 0 0 25px; font: 500 clamp(2rem, 3.7vw, 3.8rem)/1.12 var(--serif); letter-spacing: -.025em; }
.award-copy a { font: 500 10px/1 var(--mono); text-transform: uppercase; letter-spacing: .1em; text-underline-offset: 5px; }
.pillars { display: grid; grid-template-columns: 1.25fr 1fr 1fr; margin-top: 80px; border-top: 1px solid rgba(255,255,255,.3); }
.pillars article { display: grid; grid-template-columns: 40px 1fr; gap: 15px; padding: 32px 28px 32px 0; border-right: 1px solid rgba(255,255,255,.3); }
.pillars article:not(:first-child) { padding-left: 28px; }
.pillars article:last-child { border-right: 0; }
.pillars article > span { font: 500 10px/1 var(--mono); }
.pillars article p { margin-bottom: 7px; color: rgba(255,255,255,.9); font-size: 12px; }
.pillars article h3 { margin-bottom: 10px; font: 600 23px/1.1 var(--serif); }
.credit-note { margin-top: 28px; color: rgba(255,255,255,.86); font: 9px/1.6 var(--mono); }

.definition-row { display: grid; grid-template-columns: repeat(3,1fr); gap: 16px; margin-bottom: 28px; }
.definition-card { padding: 28px; border: 1px solid var(--line); background: rgba(255,255,255,.35); }
.definition-card p { margin: 15px 0 0; color: var(--muted); font-size: 13px; }
.formula { overflow-x: auto; font: 500 16px/1.5 var(--mono); letter-spacing: -.025em; }
.formula.compact { font-size: 13px; }
.formula.multiline { line-height: 1.85; }
.formula.boxed { display: inline-block; padding: 10px 14px; border: 1px solid var(--red); }

.collision-lab, .scaling-lab, .molecule-lab { display: grid; grid-template-columns: .78fr 1.22fr; margin: 28px 0 75px; }
.lab-copy { padding: 38px; }
.lab-kicker { margin-bottom: 12px; color: var(--red-deep); font: 500 9px/1 var(--mono); letter-spacing: .13em; }
.lab-copy h3 { margin-bottom: 15px; font: 600 30px/1.1 var(--serif); }
.lab-copy > p { color: var(--muted); font-size: 13px; }
.lab-copy label { display: flex; justify-content: space-between; margin-top: 25px; font: 500 10px/1 var(--mono); text-transform: uppercase; }
input[type="range"] {
  width: 100%;
  height: 24px;
  margin: 9px 0;
  appearance: none;
  background: linear-gradient(transparent 11px, var(--line) 11px, var(--line) 13px, transparent 13px);
}
input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 16px;
  height: 16px;
  border: 2px solid var(--white);
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 0 0 1px var(--red);
  cursor: pointer;
}
input[type="range"]::-moz-range-track { height: 2px; background: var(--line); }
input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border: 2px solid var(--white);
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 0 0 1px var(--red);
  cursor: pointer;
}
.small-button, .molecule-actions button, .limit-proof button {
  padding: 10px 15px;
  border: 1px solid var(--line);
  background: transparent;
  cursor: pointer;
  text-transform: uppercase;
  font: 500 9px/1 var(--mono);
  letter-spacing: .06em;
}
.small-button:hover, .molecule-actions button:hover { border-color: var(--red); }
.lab-readout { margin-top: 24px; border-top: 1px solid var(--line); }
.lab-readout div, .molecule-score div, .tree-stats div, .scaling-readout div {
  display: flex;
  justify-content: space-between;
  gap: 15px;
  padding: 11px 0;
  border-bottom: 1px solid var(--line);
  font: 9px/1.3 var(--mono);
}
.lab-readout span, .molecule-score span, .tree-stats span, .scaling-readout span { color: var(--muted); }
.lab-readout b, .molecule-score b, .tree-stats b, .scaling-readout b { font-weight: 500; }
.collision-visual { padding: 20px 25px; background: var(--navy); }
.collision-visual svg { width: 100%; height: 390px; }
.collision-visual .svg-label { fill: rgba(255,255,255,.45); font: 9px var(--mono); letter-spacing: .15em; }
.collision-visual .divider { stroke: rgba(255,255,255,.12); }
.visual-note { display: flex; justify-content: center; align-items: center; gap: 7px; color: rgba(255,255,255,.76); font: 9px/1.3 var(--mono); }
.visual-note span { width: 7px; height: 7px; border-radius: 50%; }
.red-key { background: var(--red); }.blue-key { background: var(--blue); }.gold-key { background: var(--gold); }
.stage-note, .operator-key, .notation-warning, .plain-language, .piece-legend { padding: 22px 26px; border-left: 3px solid var(--gold); background: var(--paper-2); }
.stage-note { display: grid; grid-template-columns: 180px 1fr; gap: 25px; margin: -35px 0 70px; }
.stage-note b, .operator-key b, .notation-warning b, .piece-legend b { color: var(--red-deep); font: 500 9px/1.4 var(--mono); }
.stage-note p, .operator-key p, .notation-warning, .plain-language p, .piece-legend p { margin: 0; color: var(--muted); font-size: 11px; }
.operator-key { max-width: 900px; margin: 20px auto 0; }
.notation-warning { margin: 0 0 5px; }
.plain-language { margin-top: 45px; border: 1px solid rgba(255,255,255,.2); border-left: 3px solid var(--gold); background: rgba(255,255,255,.04); }
.plain-language summary { color: white; cursor: pointer; font: 500 10px/1.4 var(--mono); }
.plain-language p { margin-top: 15px; color: rgba(255,255,255,.6); }
.lab-footnote { margin: -58px 0 65px; color: var(--muted); font: 9px/1.6 var(--mono); }
.toy-warning { margin-top: 22px; color: rgba(255,255,255,.78) !important; font: 9px/1.55 var(--mono); }
.geometric-barrier { display: grid; grid-template-columns: .7fr 1.3fr; gap: 35px; margin-top: 20px; padding: 25px; border: 1px solid rgba(255,255,255,.2); }
.geometric-barrier p { margin: 0; color: rgba(255,255,255,.6); font-size: 11px; }

.derivation { margin-top: 70px; border-top: 1px solid var(--ink); }
.derivation-title { display: grid; grid-template-columns: 100px 1fr 20px; gap: 25px; align-items: center; padding: 26px 0; border-bottom: 1px solid var(--line); }
.derivation-title p { margin: 0; }
.derivation-title h3 { margin: 0; font: 600 27px/1.1 var(--serif); }
.proof-steps { list-style: none; margin: 0; padding: 0; }
.proof-steps > li { display: grid; grid-template-columns: 100px 1fr; gap: 25px; padding: 36px 0; border-bottom: 1px solid var(--line); }
.proof-steps > li > span { color: var(--red-deep); font: 500 13px/1 var(--mono); }
.proof-steps h4 { margin-bottom: 8px; font-size: 14px; }
.proof-steps p { max-width: 760px; color: var(--muted); font-size: 13px; }
.proof-steps .formula { margin: 16px 0; color: var(--ink); }
.proof-steps .annotation { padding-left: 14px; border-left: 2px solid var(--gold); font-size: 11px; }

.dark-section { width: 100%; max-width: none; padding-left: max(24px, calc((100vw - 1180px)/2)); padding-right: max(24px, calc((100vw - 1180px)/2)); background: var(--navy); color: white; }
.dark-section .section-heading .lede { color: rgba(255,255,255,.82); }
.probability-grid { display: grid; grid-template-columns: repeat(3,1fr); border-top: 1px solid rgba(255,255,255,.15); border-bottom: 1px solid rgba(255,255,255,.15); }
.probability-grid article { position: relative; padding: 45px 28px; border-right: 1px solid rgba(255,255,255,.15); overflow: hidden; }
.probability-grid article:last-child { border-right: 0; }
.ghost-number { position: absolute; right: 10px; top: -24px; color: rgba(255,255,255,.04); font: 600 110px/1 var(--serif); }
.probability-grid h3 { font: 600 24px/1.1 var(--serif); }
.probability-grid p { color: rgba(255,255,255,.78); font-size: 12px; }
.dark-formula { color: var(--red); }
.independence-explainer { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; margin: 80px 0; align-items: center; }
.independence-visual { height: 360px; display: grid; place-items: center; position: relative; border: 1px solid rgba(255,255,255,.15); }
.cloud { position: absolute; inset: 20px; }
.cloud span { position: absolute; left: var(--x); top: var(--y); width: 18px; height: 18px; border: 1px solid var(--blue); border-radius: 50%; }
.factorization { position: relative; z-index: 2; padding: 18px 22px; display: flex; gap: 18px; background: var(--navy); font: 500 13px/1 var(--mono); }
.factorization b { color: var(--red); }
.independence-explainer h3 { font: 600 42px/1 var(--serif); }
.independence-explainer > div > p { color: rgba(255,255,255,.82); font-size: 14px; }
.tiny-proof { margin-top: 25px; padding: 20px; border-left: 2px solid var(--gold); background: rgba(255,255,255,.04); }
.tiny-proof b { font-size: 12px; }.tiny-proof p { margin: 6px 0 0; color: rgba(255,255,255,.78); font-size: 11px; }

.equation-map { padding: 60px; border: 1px solid var(--line); background: var(--white); }
.equation-main { display: flex; align-items: center; justify-content: center; gap: 25px; font: 500 clamp(1.5rem, 4vw, 3.6rem)/1.2 var(--mono); }
.eq-term { padding: 12px 18px; border-bottom: 3px solid var(--blue); }
.collision-term { border-color: var(--red); }
.eq-symbol { color: var(--muted); }
.equation-labels { display: flex; justify-content: center; gap: 15px; margin: 38px 0 28px; }
.equation-labels button {
  padding: 8px 13px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font: 500 9px/1 var(--mono);
  text-transform: uppercase;
}
.equation-labels button.active { color: var(--ink); border-color: var(--ink); }
.collision-operator { display: flex; justify-content: center; gap: 15px; align-items: center; min-height: 85px; background: var(--paper); font: 500 20px/1 var(--mono); }
.integral-symbol { font-size: 38px; }.operator-body { display: flex; gap: 12px; }
.operator-gain { color: var(--green); }.operator-loss { color: var(--red-deep); }
.operator-rate { color: var(--gold); font-size: 14px; }.operator-measure { color: var(--muted); font-size: 12px; }
.equation-explanation { max-width: 650px; margin: 30px auto 0; min-height: 85px; text-align: center; }
.equation-explanation b { color: var(--red-deep); font: 500 10px/1 var(--mono); text-transform: uppercase; }
.equation-explanation p { margin: 10px 0 0; color: var(--muted); font-size: 13px; }
.compact-derivation { margin-top: 65px; }
.proof-steps.horizontal { display: grid; grid-template-columns: repeat(4,1fr); }
.proof-steps.horizontal li { display: block; padding-right: 24px; }
.proof-steps.horizontal li > span { display: block; margin-bottom: 25px; }

.scaling-lab { grid-template-columns: .7fr .55fr .75fr; margin-top: 85px; }
.control-pair { display: flex; justify-content: space-between; align-items: center; margin: 30px 0 18px; }
.control-pair label { margin: 0; }
.control-pair select { padding: 7px 20px 7px 10px; border: 1px solid var(--line); background: transparent; font: 10px var(--mono); }
.scaling-readout { padding: 45px 30px; border-left: 1px solid var(--line); border-right: 1px solid var(--line); }
.scaling-visual { min-height: 350px; position: relative; overflow: hidden; background: var(--navy); }
.scaling-visual i { position: absolute; border: 1px solid var(--red); border-radius: 50%; transform: translate(-50%,-50%); }
.hierarchy-box { margin-top: 90px; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.hierarchy-heading { display: grid; grid-template-columns: .75fr 1.15fr 1fr; gap: 35px; align-items: start; padding: 32px 0; }
.hierarchy-heading h3 { margin: 0; font: 600 31px/1 var(--serif); }
.hierarchy-heading > p:last-child { margin: 0; color: var(--muted); font-size: 11px; }
.hierarchy-formula { padding: 35px; color: white; background: var(--ink); text-align: center; }
.hierarchy-formula .formula { color: var(--red); font-size: 14px; }
.formula-note { margin: 12px 0 0; color: rgba(255,255,255,.4); font: 8px/1.5 var(--mono); }
.hierarchy-ladder { display: grid; place-items: center; gap: 16px; padding: 35px; background: var(--paper-2); }
.hierarchy-ladder > div { display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: 15px; font: 500 13px/1 var(--mono); }
.hierarchy-ladder span { padding: 9px 13px; border: 1px solid var(--line); background: var(--white); }
.hierarchy-ladder i { color: var(--muted); font: 400 8px/1 var(--mono); }
.hierarchy-ladder > b { color: var(--red-deep); font: 500 8px/1 var(--mono); text-transform: uppercase; }
.hierarchy-ladder .closed-ladder span:last-child { border-color: var(--red); }
.hierarchy-annotations { display: grid; grid-template-columns: repeat(3,1fr); }
.hierarchy-annotations article { display: grid; grid-template-columns: 25px 1fr; gap: 10px; padding: 24px; border-top: 1px solid var(--line); border-right: 1px solid var(--line); }
.hierarchy-annotations article:last-child { border-right: 0; }
.hierarchy-annotations span { color: var(--red-deep); font: 500 9px/1 var(--mono); }
.hierarchy-annotations p { margin: 0; color: var(--muted); font-size: 10px; }

.barrier-section { padding: 140px 0; color: white; background: #8f2f28; }
.barrier-section .section-heading .lede { color: rgba(255,255,255,.9); }
.inverse-card { border-color: rgba(255,255,255,.23); background: rgba(17,29,43,.98); box-shadow: none; }
.tree-lab { display: grid; grid-template-columns: .36fr .64fr; }
.tree-lab .lab-copy { border-right: 1px solid rgba(255,255,255,.13); }
.tree-lab .lab-copy > p { color: rgba(255,255,255,.55); }
.tree-lab input[type=range] { background: rgba(255,255,255,.18); }
.tree-stats div { border-color: rgba(255,255,255,.12); }
.tree-stats span { color: rgba(255,255,255,.45); }
.tree-visual { display: grid; place-items: center; padding: 20px; overflow: hidden; }
.tree-visual svg { width: 100%; height: 420px; }
.barrier-comparison { display: grid; grid-template-columns: 1fr 60px 1fr; margin: 75px 0; }
.barrier-comparison article { padding: 38px; border: 1px solid rgba(255,255,255,.25); }
.barrier-comparison .year { color: rgba(255,255,255,.5); font: 500 10px/1 var(--mono); }
.barrier-comparison h3 { margin: 15px 0 20px; font: 600 32px/1 var(--serif); }
.barrier-comparison ul { padding-left: 18px; color: rgba(255,255,255,.65); font-size: 13px; }
.verdict { margin: 30px 0 0; padding-top: 17px; border-top: 1px solid rgba(255,255,255,.2); font: 500 9px/1.4 var(--mono); text-transform: uppercase; }
.verdict.limited { color: #ffd6c8; }.verdict.solved { color: #d7f3e3; }
.versus { display: grid; place-items: center; font-size: 26px; }

.theorem-box { display: grid; grid-template-columns: 190px 1fr; border: 1px solid var(--ink); background: var(--white); }
.theorem-sidebar { padding: 32px; color: white; background: var(--ink); }
.theorem-sidebar span { color: var(--red); font: 500 9px/1 var(--mono); letter-spacing: .1em; }
.theorem-sidebar p { margin-top: 280px; color: rgba(255,255,255,.5); font: 400 9px/1.7 var(--mono); }
.theorem-content { padding: 48px; }
.theorem-content > h3 { font: 600 35px/1.1 var(--serif); }
.theorem-statement { padding: 30px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.theorem-statement p { margin: 15px 0 0; color: var(--muted); font-size: 12px; }
.assumption-ledger { margin: 20px 0 0; border: 1px solid var(--line); }
.assumption-ledger summary { padding: 13px 16px; cursor: pointer; color: var(--red-deep); font: 500 9px/1 var(--mono); text-transform: uppercase; }
.assumption-ledger > div { padding: 5px 18px 14px; border-top: 1px solid var(--line); }
.assumption-ledger p { margin: 10px 0; color: var(--muted); font-size: 10px; }
.theorem-decoder { display: flex; flex-wrap: wrap; gap: 8px; margin: 25px 0; }
.theorem-decoder button { padding: 8px 12px; border: 1px solid var(--line); background: transparent; cursor: pointer; font: 500 11px/1 var(--mono); }
.theorem-decoder button.active { border-color: var(--red); color: var(--red-deep); }
#theoremExplanation { min-height: 52px; margin: 0; color: var(--muted); font-size: 13px; }
.proof-invariant { margin: 70px 0; padding: 45px; border: 1px solid var(--line); text-align: center; background: var(--paper-2); }
.invariant-note { color: var(--muted); font-size: 10px; }
.large-formula { font-size: clamp(1rem, 2vw, 1.4rem); }
.invariant-key { display: grid; grid-template-columns: repeat(3,1fr); gap: 20px; margin-top: 35px; padding-top: 25px; border-top: 1px solid var(--line); text-align: left; }
.invariant-key span { font-size: 11px; color: var(--muted); }
.invariant-key i { display: inline-block; width: 8px; height: 8px; margin-right: 7px; border-radius: 50%; }
.worked-example { margin: 28px 0 0; padding: 22px; color: var(--muted); border-top: 1px solid var(--line); text-align: left; font-size: 11px; }
.key-a { background: var(--blue); }.key-b { background: var(--red); }.key-c { background: var(--gold); }

.proof-roadmap { min-height: 585px; display: grid; grid-template-columns: .37fr .63fr; border: 1px solid var(--line); background: var(--white); box-shadow: var(--shadow); }
.roadmap-nav { display: flex; flex-direction: column; border-right: 1px solid var(--line); }
.proof-tab { flex: 1; display: flex; gap: 18px; align-items: center; padding: 15px 25px; border: 0; border-bottom: 1px solid var(--line); background: transparent; color: var(--muted); cursor: pointer; text-align: left; font: 500 11px/1.2 var(--sans); }
.proof-tab span { color: var(--muted); font: 9px/1 var(--mono); }
.proof-tab.active { color: white; background: var(--ink); }
.proof-tab.active span { color: var(--red); }
.roadmap-content { padding: 45px 50px; position: relative; }
.roadmap-header { display: flex; justify-content: space-between; color: var(--red-deep); font: 500 9px/1 var(--mono); letter-spacing: .08em; }
.roadmap-header > span:last-child { display: inline-flex; gap: 7px; align-items: center; }
.roadmap-header b { font-weight: 500; text-transform: uppercase; }
.roadmap-content h3 { max-width: 650px; margin: 35px 0 16px; font: 600 40px/1.04 var(--serif); }
.roadmap-content > p { color: var(--muted); font-size: 14px; }
.roadmap-details { min-height: 130px; margin: 25px 0; padding: 20px; border-left: 2px solid var(--gold); background: var(--paper); color: var(--ink-2); font-size: 12px; }
.roadmap-details .formula { margin-top: 10px; font-size: 12px; }
.roadmap-logic { display: grid; grid-template-columns: 70px 1fr; gap: 7px 15px; padding-top: 20px; border-top: 1px solid var(--line); }
.roadmap-logic span { padding-top: 3px; color: var(--red-deep); font: 500 8px/1 var(--mono); }
.roadmap-logic p { margin: 0; color: var(--muted); font-size: 11px; }
.roadmap-arrows { position: absolute; bottom: 30px; right: 35px; display: flex; gap: 8px; }
.roadmap-arrows button { padding: 9px 13px; border: 1px solid var(--line); background: transparent; cursor: pointer; font: 500 9px/1 var(--mono); }
.roadmap-arrows button:disabled { opacity: .3; cursor: default; }

.molecule-intro { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; margin: 100px 0 35px; }
.molecule-intro h3 { font: 600 38px/1 var(--serif); }
.molecule-intro > p { color: var(--muted); font-size: 14px; }
.piece-legend { margin: -15px 0 35px; }
.molecule-lab { grid-template-columns: .7fr 1.3fr; }
.molecule-actions { display: flex; flex-wrap: wrap; gap: 7px; margin: 24px 0; }
.molecule-actions button:disabled { opacity: .3; cursor: default; }
.molecule-actions .quiet { color: var(--muted); }
.molecule-score { margin-top: 20px; }
.cut-annotation { min-height: 42px; margin-top: 16px; padding: 12px; border-left: 2px solid var(--red); background: var(--paper); font: 9px/1.6 var(--mono); }
.molecule-visual { padding: 25px; background: var(--navy); }
#moleculeSvg { width: 100%; height: 520px; }
.layers line { stroke: rgba(255,255,255,.1); stroke-dasharray: 4 5; }.layers text { fill: rgba(255,255,255,.32); font: 8px var(--mono); }
.molecule-edges path { fill: none; stroke: rgba(255,255,255,.6); stroke-width: 2; }
.molecule-edges .cycle-edge { stroke: var(--red); }.molecule-edges .overlap-edge { stroke: var(--gold); stroke-dasharray: 4 4; }
.molecule-atoms circle { fill: var(--navy); stroke: var(--blue); stroke-width: 2; }
.cut-lines path { opacity: 0; fill: none; stroke: var(--gold); stroke-width: 2; stroke-dasharray: 8 5; transition: opacity .4s; }
.cut-lines path.active { opacity: 1; }
.fragment-labels text { opacity: 0; fill: var(--gold); font: 500 18px var(--mono); transition: opacity .3s; }
.fragment-labels text.active { opacity: 1; }
.molecule-legend { display: flex; justify-content: center; gap: 20px; color: rgba(255,255,255,.4); font: 8px/1 var(--mono); }
.molecule-legend i { display: inline-block; width: 13px; height: 4px; margin-right: 5px; }
.atom-key { border: 1px solid var(--blue); border-radius: 50%; }.bond-key { background: white; }.cycle-key { background: var(--red); }.cut-key { border-top: 1px dashed var(--gold); }

.estimate-chain { margin-top: 80px; }
.estimate-chain > h3 { font: 600 40px/1 var(--serif); }
.estimate-row { display: grid; grid-template-columns: 1fr 40px 1fr 40px 1fr; margin-top: 35px; align-items: stretch; }
.estimate-row article { padding: 27px; border: 1px solid var(--line); }
.estimate-row article > span { color: var(--red-deep); font: 500 9px/1 var(--mono); }
.estimate-row article .formula { margin: 30px 0; font-size: 13px; }
.estimate-row article p { color: var(--muted); font-size: 11px; }
.estimate-row .winning { color: white; background: var(--ink); }
.estimate-row .winning p { color: rgba(255,255,255,.55); }
.math-operator { display: grid; place-items: center; font: 20px var(--mono); }
.limit-proof { margin-top: 20px; }
.limit-proof button { color: var(--red-deep); border-color: var(--red); }
#limitProof { margin-top: 15px; padding: 25px; background: var(--paper-2); font-size: 12px; }
#limitProof p { margin-bottom: 8px; }
.sum-note { margin: 20px 0; padding: 18px 22px; color: var(--muted); border-left: 3px solid var(--blue); background: var(--paper-2); font-size: 10px; }
.budget-box { margin-top: 18px; border-left: 3px solid var(--gold); background: var(--paper-2); }
.budget-box summary { padding: 18px 23px; color: var(--red-deep); cursor: pointer; font: 500 9px/1.5 var(--mono); text-transform: uppercase; }
.budget-inner { display: grid; grid-template-columns: .6fr 1fr 1fr; gap: 25px; align-items: center; padding: 5px 23px 23px; }
.budget-inner > span { color: var(--red-deep); font: 500 8px/1.5 var(--mono); }
.budget-box .formula { font-size: 11px; }
.budget-box p { margin: 0; color: var(--muted); font-size: 10px; }
.elementary-grid { display: grid; grid-template-columns: repeat(4,1fr); margin-top: 80px; }
.elementary-grid article { padding: 28px; border: 1px solid var(--line); border-right: 0; }
.elementary-grid article:last-child { border-right: 1px solid var(--line); }
.elementary-grid article > span { font: 500 8px/1 var(--mono); }
.elementary-grid article h3 { margin: 10px 0; font: 600 30px/1 var(--serif); }
.elementary-grid article p { color: var(--muted); font-size: 11px; }
.elementary-grid .good > span { color: var(--green); }.elementary-grid .bad > span { color: var(--red-deep); }
.precision-note { padding: 0; border: 1px solid var(--line); border-top: 0; background: rgba(215,169,77,.08); }
.precision-note summary { padding: 18px 28px; color: var(--red-deep); cursor: pointer; font: 500 8px/1.5 var(--mono); text-transform: uppercase; }
.precision-note p { margin: 0; padding: 0 28px 22px; color: var(--muted); font-size: 10px; }
.mini-molecule { height: 85px; position: relative; }
.mini-molecule::before, .mini-molecule::after { content: ""; position: absolute; height: 1px; background: var(--ink); transform-origin: left; }
.mini-molecule::before { width: 70px; left: 25px; top: 25px; transform: rotate(25deg); }
.mini-molecule::after { width: 70px; left: 25px; top: 58px; transform: rotate(-25deg); }
.mini-molecule i { position: absolute; width: 10px; height: 10px; border-radius: 50%; background: var(--paper); border: 1px solid var(--ink); }
.mini-molecule i:nth-child(1) { left: 18px; top: 37px; }.mini-molecule i:nth-child(2) { left: 90px; top: 17px; }
.mini-molecule i:nth-child(3) { left: 90px; top: 57px; }.mini-molecule i:nth-child(4) { left: 52px; top: 37px; border-color: var(--red); }
.proof-close { display: grid; grid-template-columns: 1fr 35px 1fr 35px 1fr 35px 1fr; margin-top: 80px; align-items: center; }
.close-step { padding: 20px; min-height: 125px; border-top: 2px solid var(--blue); background: var(--paper-2); }
.close-step > span { color: var(--red-deep); font: 500 10px/1 var(--mono); }
.close-step p { margin: 17px 0 0; color: var(--muted); font-size: 11px; }
.proof-close > i { height: 1px; background: var(--ink); }
.close-step.conclusion { border-color: var(--red); color: white; background: var(--ink); }
.close-step.conclusion p { color: rgba(255,255,255,.65); }

.fluids-section { color: white; background: var(--navy); }
.fluids-section > .page-section { padding-top: 140px; padding-bottom: 120px; }
.fluids-section .section-heading .lede { color: rgba(255,255,255,.55); }
.maxwellian-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 75px; align-items: center; }
.maxwellian-visual { border: 1px solid rgba(255,255,255,.15); }
.maxwellian-visual canvas { width: 100%; height: 470px; }
.maxwell-controls { display: grid; grid-template-columns: 1fr 1fr; gap: 25px; padding: 15px 20px; border-top: 1px solid rgba(255,255,255,.15); }
.maxwell-controls label { color: rgba(255,255,255,.55); font: 8px/1 var(--mono); }
.maxwell-controls output { float: right; color: var(--red); }
.maxwell-controls input { margin: 11px 0; background: rgba(255,255,255,.2); }
.maxwellian-grid h3 { font: 600 42px/1 var(--serif); }
.maxwell-formula { margin: 25px 0 35px; color: var(--red); }
.fraction { display: inline-flex; flex-direction: column; vertical-align: middle; text-align: center; }
.fraction i { padding: 1px 5px; font-style: normal; }.fraction i:first-child { border-bottom: 1px solid currentColor; }
.symbol-list { margin: 0; }
.symbol-list div { display: grid; grid-template-columns: 45px 1fr; padding: 11px 0; border-top: 1px solid rgba(255,255,255,.13); }
.symbol-list dt { color: var(--red); font: 500 13px var(--mono); }
.symbol-list dd { margin: 0; color: rgba(255,255,255,.55); font-size: 11px; }
.moment-identities { margin-top: 28px; padding-top: 20px; border-top: 1px solid rgba(255,255,255,.15); }
.moment-identities .formula { color: var(--red); font-size: 10px; }
.moment-identities p, .fluid-scaling-note { color: rgba(255,255,255,.55); font-size: 10px; }
.fluid-scaling-note { padding: 22px; border-left: 3px solid var(--gold); background: rgba(255,255,255,.04); }
.fluid-branches { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 80px 0; }
.fluid-branches article { padding: 35px; border: 1px solid rgba(255,255,255,.15); }
.fluid-branches article > p { color: var(--red); font: 500 9px/1 var(--mono); text-transform: uppercase; }
.fluid-branches h3 { font: 600 30px/1.1 var(--serif); }
.fluid-branches .formula { color: rgba(255,255,255,.7); font-size: 12px; }
.scope-box { padding: 38px; border-top: 1px solid white; border-bottom: 1px solid white; }
.scope-box h3 { font: 600 32px/1 var(--serif); }
.scope-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; }
.scope-columns span { font: 500 9px/1 var(--mono); }.scope-columns .yes { color: var(--green); }.scope-columns .no { color: var(--red); }
.scope-columns p { color: rgba(255,255,255,.55); font-size: 12px; }
.time-band { padding: 110px 0; background: #0b141e; }
.time-grid { display: grid; grid-template-columns: .7fr 1.15fr .95fr; gap: 55px; align-items: start; }
.time-grid h2 { font-size: clamp(3rem, 5vw, 5rem); }
.time-toggle { border: 1px solid rgba(255,255,255,.15); }
.time-toggle button { width: 100%; padding: 14px; border: 0; border-bottom: 1px solid rgba(255,255,255,.15); color: var(--red); background: transparent; cursor: pointer; font: 500 9px/1 var(--mono); }
.time-toggle canvas { width: 100%; height: 260px; }
.time-toggle > p { margin: 0; padding: 12px; color: rgba(255,255,255,.75); font: 9px/1.5 var(--mono); }
.time-explanation ol { list-style: none; margin: 0; padding: 0; }
.time-explanation li { display: grid; grid-template-columns: 30px 1fr; gap: 10px; padding: 12px 0; border-bottom: 1px solid rgba(255,255,255,.12); }
.time-explanation li span { color: var(--red); font: 500 9px/1 var(--mono); }
.time-explanation li p { margin: 0; color: rgba(255,255,255,.8); font-size: 11px; }
.time-explanation .caveat { margin-top: 20px; color: rgba(255,255,255,.72); font: 9px/1.6 var(--mono); }
.equation-caption { margin-top: 16px !important; color: rgba(255,255,255,.5) !important; font: 400 9px/1.6 var(--mono) !important; text-transform: none !important; }
.credit-bridge { display: grid; grid-template-columns: 1fr 60px 1fr; align-items: stretch; margin: 0 0 55px; border: 1px solid rgba(255,255,255,.16); }
.credit-bridge > div { padding: 30px; }
.credit-bridge > div:first-child { background: rgba(231,95,67,.08); }
.credit-bridge > i { display: grid; place-items: center; color: var(--red); border-right: 1px solid rgba(255,255,255,.12); border-left: 1px solid rgba(255,255,255,.12); font: normal 24px/1 var(--mono); }
.credit-bridge span { color: var(--red); font: 500 8px/1 var(--mono); letter-spacing: .1em; }
.credit-bridge h3 { margin: 12px 0 8px; font: 600 25px/1 var(--serif); }
.credit-bridge p { margin: 0; color: rgba(255,255,255,.52); font-size: 11px; }
.entropy-proof { margin-top: 90px; padding-top: 35px; border-top: 1px solid rgba(255,255,255,.2); }
.entropy-proof > div:first-child { display: flex; justify-content: space-between; align-items: baseline; gap: 30px; }
.entropy-proof h3 { font: 600 34px/1 var(--serif); }
.entropy-steps { display: grid; grid-template-columns: repeat(4,1fr); margin-top: 25px; }
.entropy-steps article { min-height: 220px; padding: 25px; border: 1px solid rgba(255,255,255,.13); border-right: 0; }
.entropy-steps article:last-child { border-right: 1px solid rgba(255,255,255,.13); }
.entropy-steps article > span { color: var(--red); font: 500 8px/1 var(--mono); }
.entropy-steps .formula { margin: 28px 0 18px; font-size: 11px; }
.entropy-steps p { color: rgba(255,255,255,.5); font-size: 10px; }

.method-bridge { display: grid; grid-template-columns: 1fr .65fr 1fr; gap: 20px; align-items: stretch; }
.method-bridge article { padding: 35px; border: 1px solid var(--line); background: var(--white); }
.method-bridge article > span { color: var(--red-deep); font: 500 9px/1 var(--mono); }
.method-bridge h3 { margin: 15px 0; font: 600 29px/1.05 var(--serif); }
.method-bridge article p { color: var(--muted); font-size: 12px; }
.bridge-core { display: flex; flex-direction: column; justify-content: center; gap: 8px; padding: 30px; color: white; background: var(--ink); }
.bridge-core span { margin-bottom: 15px; color: var(--red); font: 500 8px/1 var(--mono); }
.bridge-core b { font: 500 12px/1.5 var(--mono); }
.method-specifics { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 20px 0 90px; }
.method-specifics article { padding: 24px 30px; border-left: 3px solid var(--blue); background: var(--paper-2); }
.method-specifics article:last-child { border-color: var(--red); }
.method-specifics span { color: var(--red-deep); font: 500 8px/1 var(--mono); letter-spacing: .08em; }
.method-specifics p { margin-bottom: 0; color: var(--muted); font-size: 11px; }
.dialect-table-wrap { margin: 0 0 65px; }
.dialect-table-wrap > h3 { margin: 8px 0; font: 600 38px/1 var(--serif); }
.table-lede { max-width: 800px; color: var(--muted); font-size: 12px; }
.dialect-table { margin-top: 30px; border-top: 1px solid var(--ink); }
.table-row { display: grid; grid-template-columns: .65fr repeat(3,1fr); border-bottom: 1px solid var(--line); }
.table-row > * { margin: 0; padding: 17px 16px; border-right: 1px solid var(--line); font-size: 10px; }
.table-row > *:last-child { border-right: 0; }
.table-row > span { color: var(--red-deep); font: 500 8px/1.4 var(--mono); text-transform: uppercase; }
.table-row > p { color: var(--muted); }
.table-head { color: white; background: var(--ink); }
.table-head > * { color: white; border-color: rgba(255,255,255,.14); font: 500 9px/1.4 var(--mono); }
.related-pillars { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 25px 0 100px; }
.related-pillars article { padding: 38px; border: 1px solid var(--line); }
.related-pillars h3 { font: 600 34px/1 var(--serif); }
.related-pillars > article > p:not(.lab-kicker) { color: var(--muted); font-size: 12px; }
.related-pillars a { color: var(--red-deep); font: 500 9px/1 var(--mono); text-underline-offset: 4px; }
.mini-pipeline { display: flex; gap: 10px; align-items: center; margin: 25px 0; color: var(--muted); font: 9px/1.3 var(--mono); }
.mini-pipeline i { color: var(--red); font-style: normal; }
.inline-links { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.inline-links a { padding: 8px 10px; border: 1px solid var(--line); text-decoration: none; }
.rough-steps { list-style: none; margin: 25px 0; padding: 0; }
.rough-steps li { display: grid; grid-template-columns: 28px 1fr; gap: 10px; padding: 10px 0; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 11px; }
.rough-steps li span { color: var(--red-deep); font: 500 9px/1 var(--mono); }

.resonance-lab { display: grid; grid-template-columns: .75fr 1.25fr; margin: 0 0 25px; }
.resonance-readout { margin-top: 25px; border-top: 1px solid var(--line); }
.resonance-readout div { display: flex; justify-content: space-between; gap: 15px; padding: 10px 0; border-bottom: 1px solid var(--line); font: 8px/1.4 var(--mono); }
.resonance-readout span { color: var(--muted); }
.resonance-readout b { color: var(--red-deep); font-weight: 500; }
.resonance-visual { padding: 22px; background: var(--navy); }
.resonance-visual svg { width: 100%; min-height: 390px; }
.res-grid line { stroke: rgba(255,255,255,.06); }
.res-shape line, .res-shape path { fill: none; stroke: var(--blue); stroke-width: 2; }
.res-shape .diagonal { stroke: var(--red); stroke-dasharray: 6 5; }
.res-shape circle { fill: var(--navy); stroke: var(--red); stroke-width: 2; }
.res-labels text { fill: white; font: 11px var(--mono); }
.resonance-equations { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; padding-top: 14px; border-top: 1px solid rgba(255,255,255,.12); color: rgba(255,255,255,.5); font: 8px/1.4 var(--mono); }
.oscillation-note { margin: 15px 0 0; color: rgba(255,255,255,.58); font: 9px/1.5 var(--mono); }
.wke-formula { display: grid; grid-template-columns: .8fr 1.2fr; gap: 50px; align-items: center; margin: 25px 0 80px; padding: 35px; border: 1px solid var(--line); }
.wke-formula h3 { margin: 8px 0; font: 600 30px/1 var(--serif); }
.wke-formula p:last-child { color: var(--muted); font-size: 11px; }
.wke-formula > .formula, .wke-formula > div:last-child > .formula { padding: 25px; color: var(--red-deep); background: var(--paper-2); font-size: 11px; }
.formula-note.dark-note { color: var(--muted); }
.rough-field-box { display: grid; grid-template-columns: .75fr 1fr 1fr; margin: 0 0 95px; border-top: 1px solid var(--ink); border-left: 1px solid var(--line); }
.rough-field-box > div { padding: 28px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.rough-field-box h3 { font: 600 30px/1 var(--serif); }
.rough-field-box .formula { font-size: 11px; }
.rough-field-box p { color: var(--muted); font-size: 10px; }
.rough-thresholds { grid-column: 1 / -1; display: grid; grid-template-columns: .6fr 1fr 1.2fr; gap: 25px; align-items: center; background: var(--paper-2); }
.rough-thresholds > span { color: var(--red-deep); font: 500 8px/1.5 var(--mono); }

.prior-regimes { display: grid; grid-template-columns: .7fr 1.3fr; gap: 55px; margin-top: 100px; padding-top: 40px; border-top: 1px solid var(--ink); }
.prior-regimes > div:first-child h3 { margin: 10px 0; font: 600 34px/1 var(--serif); }
.prior-regimes > div:first-child > p:last-child { color: var(--muted); font-size: 11px; }
.regime-grid { display: grid; grid-template-columns: 1fr 1fr; }
.regime-grid article { min-height: 190px; padding: 25px; border: 1px solid var(--line); border-right: 0; border-bottom: 0; }
.regime-grid article:nth-child(2n) { border-right: 1px solid var(--line); }
.regime-grid article:nth-last-child(-n+2) { border-bottom: 1px solid var(--line); }
.regime-grid article > span { color: var(--red-deep); font: 500 8px/1 var(--mono); }
.regime-grid h4 { margin: 18px 0 8px; font: 600 21px/1.05 var(--serif); }
.regime-grid p { color: var(--muted); font-size: 10px; }
.regime-grid .breakthrough { color: white; background: var(--ink); }
.regime-grid .breakthrough p { color: rgba(255,255,255,.55); }
.regime-grid .breakthrough span { color: var(--red); }
.timeline-section { margin-top: 80px; }
.timeline-section > h3 { font: 600 43px/1 var(--serif); }
.timeline { display: grid; grid-template-columns: repeat(8,1fr); margin-top: 35px; border-bottom: 1px solid var(--ink); }
.timeline button { min-height: 105px; padding: 12px 8px; border: 0; border-right: 1px solid var(--line); background: transparent; cursor: pointer; text-align: left; }
.timeline button span { display: block; margin-bottom: 18px; color: var(--muted); font: 500 8px/1 var(--mono); }
.timeline button b { font-size: 10px; }
.timeline button.active { color: white; background: var(--ink); }
.timeline button.active span { color: var(--red); }
.timeline-detail { display: grid; grid-template-columns: 100px 1.2fr .8fr; gap: 35px; min-height: 180px; padding: 35px; background: var(--paper-2); }
.timeline-detail > span { color: var(--red-deep); font: 500 20px/1 var(--mono); }
.timeline-detail h4 { margin-bottom: 9px; font: 600 25px/1.1 var(--serif); }
.timeline-detail p { margin: 0; color: var(--muted); font-size: 11px; }
.timeline-detail .why { padding-left: 20px; border-left: 1px solid var(--line); }
.timeline-detail .why b { display: block; margin-bottom: 8px; color: var(--ink); font: 500 8px/1 var(--mono); text-transform: uppercase; }
.historical-branches { display: grid; grid-template-columns: 1fr 1fr; margin-top: 20px; }
.historical-branches article { padding: 25px; border: 1px solid var(--line); border-right: 0; background: var(--paper-2); }
.historical-branches article:last-child { border-right: 1px solid var(--line); }
.historical-branches span { color: var(--red-deep); font: 500 8px/1 var(--mono); }
.historical-branches p { margin: 12px 0 0; color: var(--muted); font-size: 10px; }
.dependency-map { margin-top: 100px; border: 1px solid var(--line); background: var(--white); }
.dependency-heading { padding: 35px 40px 0; }
.dependency-heading h3 { font: 600 35px/1 var(--serif); }
.dependency-map svg { width: 100%; }
.dep-lines path { fill: none; stroke: var(--muted); stroke-width: 1; marker-end: url(#depArrow); }
#depArrow path { fill: var(--muted); }
.dep-nodes rect { fill: var(--paper); stroke: var(--line); }
.dep-nodes text { text-anchor: middle; fill: var(--ink); font: 9px var(--mono); }
.dep-nodes .target rect { fill: var(--ink); stroke: var(--red); }.dep-nodes .target text { fill: white; }
.frontiers { margin-top: 110px; }
.frontier-grid { display: grid; grid-template-columns: repeat(3,1fr); }
.frontier-grid article { min-height: 245px; padding: 28px; border: 1px solid var(--line); border-right: 0; border-bottom: 0; }
.frontier-grid article:nth-child(3n) { border-right: 1px solid var(--line); }
.frontier-grid article:nth-last-child(-n+3) { border-bottom: 1px solid var(--line); }
.frontier-grid h3 { margin: 20px 0 9px; font: 600 24px/1 var(--serif); }
.frontier-grid p { color: var(--muted); font-size: 10px; }
.frontier-grid a { color: var(--red-deep); font: 500 8px/1 var(--mono); }
.status { display: inline-block; padding: 5px 7px; color: var(--ink); border: 1px solid var(--line); font: 500 7px/1 var(--mono); letter-spacing: .08em; }
.status.extension { color: #285c47; border-color: var(--green); }
.status.bridge { color: #7c5d1e; border-color: var(--gold); }
.status.open { color: var(--red-deep); border-color: var(--red); }

.glossary-section { padding: 130px 0; color: white; background: #8f2f28; }
.search-box { display: flex; gap: 12px; align-items: center; padding: 12px 17px; border-bottom: 1px solid rgba(255,255,255,.5); }
.search-box input { width: 260px; border: 0; color: white; background: transparent; font: 11px/1 var(--mono); }
.search-box:focus-within { outline: 2px solid white; outline-offset: 2px; box-shadow: 0 0 0 5px var(--ink); }
.search-box input::placeholder { color: rgba(255,255,255,.8); }
.glossary-grid { display: grid; grid-template-columns: repeat(4,1fr); }
.glossary-grid article { min-height: 190px; padding: 28px; border: 1px solid rgba(255,255,255,.27); border-right: 0; border-bottom: 0; }
.glossary-grid article:nth-child(4n) { border-right: 1px solid rgba(255,255,255,.27); }
.glossary-grid article:nth-last-child(-n+4) { border-bottom: 1px solid rgba(255,255,255,.27); }
.glossary-grid article[hidden] { display: none; }
.glossary-grid article > b { font: 500 18px/1 var(--mono); }
.glossary-grid h3 { margin: 35px 0 7px; font: 600 20px/1 var(--serif); }
.glossary-grid p { color: rgba(255,255,255,.9); font-size: 11px; }
.no-results { padding: 30px; border: 1px solid rgba(255,255,255,.3); }

.quiz { border-top: 1px solid var(--ink); }
.quiz article { display: grid; grid-template-columns: .65fr 1.35fr; gap: 40px; padding: 28px 0; border-bottom: 1px solid var(--line); position: relative; }
.quiz article > p:first-child { font: 600 15px/1.5 var(--sans); }
.quiz article > p span { margin-right: 18px; color: var(--red-deep); font: 500 9px/1 var(--mono); }
.quiz article > div { display: flex; flex-wrap: wrap; gap: 8px; }
.quiz button { min-height: 44px; padding: 11px 13px; border: 1px solid var(--line); background: transparent; cursor: pointer; font-size: 11px; }
.quiz button:hover { border-color: var(--ink); }
.quiz button.correct { border-color: var(--green); color: #236044; background: rgba(106,165,135,.1); }
.quiz button.incorrect { border-color: var(--red); color: var(--red-deep); }
.quiz-feedback { position: static; grid-column: 2; min-height: 2.8em; margin: 4px 0 0; color: var(--muted); font: 500 11px/1.5 var(--mono); }

/* Second-edition worked examples and visual checkpoints */
.live-algebra { margin-top: 20px; border: 1px solid var(--line); background: var(--paper); }
.live-algebra summary { padding: 12px 14px; color: var(--red-deep); cursor: pointer; font: 500 8px/1.4 var(--mono); text-transform: uppercase; letter-spacing: .06em; }
.live-algebra > div { padding: 0 14px 10px; }
.live-algebra p { display: grid; grid-template-columns: 105px 1fr; gap: 10px; margin: 0; padding: 8px 0; border-top: 1px solid var(--line); }
.live-algebra span { color: var(--muted); font: 7px/1.4 var(--mono); text-transform: uppercase; }
.live-algebra code { overflow-wrap: anywhere; color: var(--ink); font: 500 8px/1.5 var(--mono); }

.worked-bridge { display: grid; grid-template-columns: 1.2fr .8fr; gap: 0; margin: 0 0 80px; border: 1px solid var(--line); border-top: 3px solid var(--gold); background: var(--white); }
.worked-bridge > div { padding: 34px; }
.worked-bridge > div + div { border-left: 1px solid var(--line); background: var(--paper-2); }
.worked-bridge h3 { max-width: 520px; font: 600 32px/1.05 var(--serif); }
.worked-bridge p { color: var(--muted); font-size: 12px; }
.worked-bridge .formula { margin: 16px 0; font-size: 12px; }
.numeric-example > span, .cumulant-worked span, .resonance-worked span, .entropy-number-example > span { color: var(--red-deep); font: 500 8px/1.4 var(--mono); letter-spacing: .08em; }
.numeric-example dl { margin: 20px 0; }
.numeric-example dl div { display: flex; justify-content: space-between; gap: 20px; padding: 8px 0; border-top: 1px solid var(--line); font: 9px/1.4 var(--mono); }
.numeric-example dt { color: var(--muted); }.numeric-example dd { margin: 0; }
.oblique-example { margin: 18px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.oblique-example summary, .number-detail summary { padding: 13px 0; color: var(--red-deep); cursor: pointer; font: 500 9px/1.4 var(--mono); text-transform: uppercase; }
.oblique-example .formula { font-size: 9px; }
.number-detail { margin: -45px 0 65px; padding: 0 24px; border-left: 3px solid var(--blue); background: var(--paper-2); }
.number-detail > div { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 25px; padding: 4px 0 20px; }
.number-detail p { margin: 0; color: var(--muted); font-size: 10px; }
.number-detail .formula { font-size: 10px; }

.visual-quiz { display: grid; grid-template-columns: minmax(290px,.85fr) minmax(0,1.15fr); margin: 70px 0; border: 1px solid var(--line); background: var(--white); box-shadow: var(--shadow); }
.visual-quiz-copy, .visual-quiz-visual { padding: 34px; }
.visual-quiz-copy { border-right: 1px solid var(--line); }
.visual-quiz-copy h3 { margin-bottom: 12px; font: 600 31px/1.06 var(--serif); }
.visual-quiz-copy > p:not(.lab-kicker):not(.checkpoint-feedback):not(.challenge-goal) { color: var(--muted); font-size: 12px; }
.visual-quiz-copy > label, .density-controls label { display: flex; justify-content: space-between; gap: 20px; margin-top: 18px; font: 500 9px/1.4 var(--mono); text-transform: uppercase; }
.checkpoint-check, .preset-row button, .tree-mode button, .quiz-score button {
  min-height: 44px; padding: 10px 14px; border: 1px solid var(--line); background: transparent; cursor: pointer; font: 500 10px/1.2 var(--mono); text-transform: uppercase; letter-spacing: .05em;
}
.checkpoint-check:hover, .checkpoint-check:focus-visible, .preset-row button:hover, .tree-mode button:hover { border-color: var(--red); }
.checkpoint-feedback { min-height: 3.5em; margin: 14px 0 0; color: var(--muted); font: 500 11px/1.5 var(--mono); }
.checkpoint-feedback.success { color: #236044; }.checkpoint-feedback.error { color: var(--red-deep); }
.challenge-goal { padding: 11px 13px; border-left: 2px solid var(--gold); background: var(--paper-2); color: var(--ink-2); font: 500 9px/1.5 var(--mono); }
.preset-row { display: flex; flex-wrap: wrap; gap: 7px; margin: 17px 0 5px; }
.choice-set { margin: 18px 0; padding: 0; border: 0; }
.choice-set legend { margin-bottom: 9px; color: var(--red-deep); font: 500 8px/1.4 var(--mono); text-transform: uppercase; }
.choice-set label { display: flex; gap: 9px; align-items: center; min-height: 44px; color: var(--ink-2); font-size: 12px; }
.choice-set input { accent-color: var(--red); }
.quiz-readout { margin: 20px 0 0; border-top: 1px solid var(--line); }
.quiz-readout div { display: flex; justify-content: space-between; gap: 20px; padding: 10px 0; border-bottom: 1px solid var(--line); font: 9px/1.4 var(--mono); }
.quiz-readout dt { color: var(--muted); }.quiz-readout dd { margin: 0; text-align: right; }
.lab-footnote-inline { margin: 18px 0 0; color: var(--muted); font: 8px/1.6 var(--mono); }
.sr-only { position: absolute !important; width: 1px !important; height: 1px !important; padding: 0 !important; margin: -1px !important; overflow: hidden !important; clip: rect(0,0,0,0) !important; white-space: nowrap !important; border: 0 !important; }

.chaos-quiz { border-color: rgba(255,255,255,.2); background: rgba(255,255,255,.035); box-shadow: none; }
.chaos-quiz .visual-quiz-copy { border-color: rgba(255,255,255,.16); }
.chaos-quiz h3, .chaos-quiz h4 { color: white; }
.chaos-quiz .visual-quiz-copy > p, .chaos-quiz .challenge-goal, .chaos-quiz .quiz-readout dt, .chaos-quiz .lab-footnote-inline { color: rgba(255,255,255,.82); }
.chaos-quiz .challenge-goal { background: rgba(255,255,255,.04); }
.chaos-quiz .preset-row button, .chaos-quiz .checkpoint-check { color: white; border-color: rgba(255,255,255,.2); }
.chaos-quiz .quiz-readout, .chaos-quiz .quiz-readout div { border-color: rgba(255,255,255,.15); }
.joint-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.joint-grid h4 { grid-column: 1/-1; margin: 0 0 8px; font: 600 18px/1 var(--serif); }
.joint-grid > div { aspect-ratio: 1.55; display: flex; flex-direction: column; justify-content: space-between; padding: 15px; border: 1px solid rgba(255,255,255,.17); background: rgba(118,167,197,var(--prob-alpha,.1)); }
.joint-grid span { color: rgba(255,255,255,.58); font: 8px/1.4 var(--mono); }.joint-grid b { color: white; font: 500 21px/1 var(--mono); }

.ledger-quiz { margin-top: 30px; }
.density-controls { display: grid; grid-template-columns: 1fr 1fr; gap: 0 18px; }
.density-controls input { margin-bottom: 2px; }
.ledger-bars h4, .budget-race h4 { margin: 0 0 24px; font: 600 21px/1 var(--serif); }
.ledger-bars > div { display: grid; grid-template-columns: 150px 1fr 55px; gap: 12px; align-items: center; margin: 17px 0; font: 9px/1.4 var(--mono); }
.ledger-bars > div > i { display: block; height: 26px; width: var(--bar-width,20%); min-width: 2px; background: var(--green); transition: width .2s; }
.ledger-bars > div:nth-of-type(2) > i { background: var(--red); }
.ledger-bars .ledger-net { padding-top: 17px; border-top: 1px solid var(--line); }
.ledger-bars .ledger-net > i { background: var(--gold); }
.ledger-calculation { margin-top: 25px; padding: 20px; color: var(--red-deep); background: var(--paper-2); font-size: 13px; }
.ledger-visual > p { color: var(--muted); font-size: 10px; }

.bbgky-contact-derivation { display: grid; grid-template-columns: .75fr 1.15fr 1.1fr; border: 1px solid var(--line); border-top: 0; }
.bbgky-contact-derivation > div { padding: 28px; border-right: 1px solid var(--line); }
.bbgky-contact-derivation > div:last-child { border-right: 0; }
.contact-visual { display: grid; place-items: center; background: var(--paper-2); }
.contact-visual svg { width: 100%; }
.contact-shell { fill: none; stroke: var(--blue); stroke-dasharray: 5 5; }
.contact-particle { stroke-width: 2; }.contact-particle.one { fill: rgba(231,95,67,.15); stroke: var(--red); }.contact-particle.two { fill: rgba(118,167,197,.18); stroke: var(--blue); }
.contact-normal { stroke: var(--gold); stroke-width: 2; }.contact-path { stroke: var(--red); stroke-width: 2; }
#contactArrow path { fill: var(--red); }.contact-visual text { fill: var(--ink-2); font: 9px var(--mono); }
.contact-copy ol { list-style: none; margin: 15px 0 0; padding: 0; }
.contact-copy li { display: grid; grid-template-columns: 22px 1fr; gap: 9px; padding: 7px 0; border-top: 1px solid var(--line); }
.contact-copy li span { color: var(--red-deep); font: 500 8px/1 var(--mono); }.contact-copy li p { margin: 0; color: var(--muted); font-size: 9px; }
.contact-formulas .formula { font-size: 9px; }
.contact-formulas p { color: var(--muted); font-size: 9px; }
.bridge-arrow { margin: 20px 0; color: var(--red-deep); text-align: center; font: 500 8px/1 var(--mono); text-transform: uppercase; }

.tree-mode { display: flex; gap: 7px; margin: 20px 0; }
.tree-mode button { color: rgba(255,255,255,.65); border-color: rgba(255,255,255,.2); }
.tree-mode button.active { color: var(--navy); background: white; }
.true-tree-example { margin-top: 25px; padding: 32px; border: 1px solid rgba(255,255,255,.27); background: rgba(16,29,44,.22); }
.true-tree-example h3 { font: 600 30px/1 var(--serif); }
.true-tree-example > p { color: rgba(255,255,255,.68); font-size: 11px; }
.tree-count-flow { display: grid; grid-template-columns: 1fr 30px 1.25fr 30px 1.55fr 30px 1.2fr; align-items: center; margin: 25px 0; }
.tree-count-flow span { min-height: 85px; display: grid; place-items: center; padding: 15px; border: 1px solid rgba(255,255,255,.18); text-align: center; font: 9px/1.5 var(--mono); }
.tree-count-flow i { color: var(--gold); text-align: center; font-style: normal; }

.cumulant-worked { display: grid; grid-template-columns: 1fr 1fr; margin-top: 24px; border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.cumulant-worked > div, .cumulant-worked > p { margin: 0; padding: 24px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.cumulant-worked .formula { margin-top: 12px; font-size: 10px; }
.cumulant-worked > p { grid-column: 1/-1; color: var(--muted); font-size: 10px; background: var(--paper-2); }
.two-layer-induction { margin: 60px 0; padding-top: 30px; border-top: 1px solid var(--ink); }
.two-layer-induction h3 { margin: 7px 0 25px; font: 600 35px/1 var(--serif); }
.layer-choice-grid { display: grid; grid-template-columns: repeat(3,1fr); }
.layer-choice-grid article { padding: 25px; border: 1px solid var(--line); border-right: 0; }
.layer-choice-grid article:last-child { border-right: 1px solid var(--line); }
.layer-choice-grid span { color: var(--red-deep); font: 500 8px/1.4 var(--mono); }.layer-choice-grid .right span { color: #236044; }
.layer-choice-grid .right { border-top: 3px solid var(--green); background: rgba(106,165,135,.08); }
.layer-choice-grid .wrong { border-top: 3px solid var(--red); }
.layer-choice-grid .formula { margin: 25px 0; font-size: 11px; }.layer-choice-grid p { color: var(--muted); font-size: 10px; }
.toy-recurrence { display: grid; grid-template-columns: 1fr 1.2fr; gap: 15px; align-items: center; padding: 25px; background: var(--ink); color: white; }
.toy-recurrence .formula { color: var(--red); font-size: 11px; }.toy-recurrence p { grid-column: 1/-1; margin: 0; color: rgba(255,255,255,.5); font-size: 9px; }

.duhamel-identification { display: grid; grid-template-columns: .8fr 1.2fr; gap: 35px; margin: 65px 0 10px; padding: 35px; border: 1px solid var(--line); background: var(--paper-2); }
.duhamel-identification h3 { font: 600 34px/1 var(--serif); }
.duhamel-identification p { color: var(--muted); font-size: 11px; }
.duhamel-identification .formula { margin: 20px 0; font-size: 11px; }
.duhamel-visual { display: grid; grid-template-columns: 1fr 65px 1fr; align-items: center; position: relative; }
.tree-twin { text-align: center; }.tree-twin svg { width: 100%; max-height: 190px; }
.tree-twin path { fill: none; stroke: var(--ink); stroke-width: 2; }.tree-twin circle { fill: var(--red); }
.tree-twin span { font: 500 8px/1.4 var(--mono); text-transform: uppercase; }
.duhamel-visual > i { color: var(--red-deep); text-align: center; font: normal 8px/1.4 var(--mono); }
.recollision-edge { grid-column: 1/-1; display: flex; justify-content: space-between; padding: 11px 14px; border-left: 3px solid var(--red); background: rgba(231,95,67,.08); font: 8px/1.4 var(--mono); }
.duhamel-caveat { grid-column: 1/-1; margin: 0; padding-top: 18px; border-top: 1px solid var(--line); }

.thin-target-example { display: grid; grid-template-columns: .65fr 1.35fr; gap: 35px; align-items: center; margin: 25px 0; padding: 28px; border: 1px solid var(--line); }
.thin-target-example h3 { margin: 8px 0; font: 600 29px/1 var(--serif); }
.thin-target-example p { color: var(--muted); font-size: 11px; }
.thin-target-visual { height: 190px; position: relative; overflow: hidden; background: var(--navy); }
.target-track { position: absolute; left: 15%; right: 8%; top: 50%; height: 1px; background: rgba(255,255,255,.5); }
.target-tube { position: absolute; left: 15%; right: 8%; top: calc(50% - 25px); height: 50px; border: 1px dashed var(--gold); background: rgba(215,169,77,.08); }
.target-particle { position: absolute; right: 18%; top: calc(50% - 11px); width: 22px; height: 22px; border: 2px solid var(--red); border-radius: 50%; }
.thin-target-visual b { position: absolute; right: 20%; top: 25%; color: var(--gold); font: 500 10px/1 var(--mono); }
.molecule-caveat { margin-top: 12px !important; }

.proof-budget-lab { margin: 40px 0 80px; }
.budget-race > div { display: grid; grid-template-columns: 130px 1fr 75px; gap: 12px; align-items: center; margin: 19px 0; font: 9px/1.4 var(--mono); }
.budget-race .race-axis { grid-template-columns: 1fr 2px 1fr; color: var(--muted); text-align: center; }
.race-axis i { height: 20px; background: var(--ink); }
.budget-race > div > i:not(.loss-side):not(.gain-side) { height: 24px; background: var(--gold); }
.budget-race .loss-side, .budget-race .gain-side { display: block; height: 23px; width: var(--bar-width,30%); }
.budget-race .loss-side { justify-self: center; background: var(--red); }.budget-race .gain-side { justify-self: center; background: var(--green); }
.budget-race .race-net { padding-top: 14px; border-top: 1px solid var(--line); }
.budget-race .race-net i { width: 7px; transform: translateX(var(--marker-x,0)); transition: transform .2s; }
.budget-formula { margin-top: 25px; padding: 18px; background: var(--paper-2); font-size: 11px; }
.budget-race + .formula + p { color: var(--muted); font-size: 10px; }

.formal-caveat { max-width: 850px; color: rgba(255,255,255,.48); font: 8px/1.6 var(--mono); }
.entropy-number-example { display: grid; grid-template-columns: .35fr 1fr 1fr; gap: 25px; align-items: center; margin-top: 20px; padding: 24px; border-left: 3px solid var(--gold); background: rgba(255,255,255,.04); }
.entropy-number-example .formula { color: var(--red); font-size: 10px; }.entropy-number-example p { margin: 0; color: rgba(255,255,255,.55); font-size: 10px; }

.pillar-matcher { margin: 0 0 70px; padding: 35px; border: 1px solid var(--line); background: var(--paper-2); }
.pillar-matcher h3 { font: 600 33px/1 var(--serif); }.pillar-matcher > div:first-child > p:last-child { color: var(--muted); font-size: 11px; }
.matcher-grid { display: grid; grid-template-columns: repeat(3,1fr); margin: 25px 0; }
.matcher-grid label { display: flex; flex-direction: column; gap: 16px; padding: 24px; border: 1px solid var(--line); border-right: 0; }
.matcher-grid label:last-child { border-right: 1px solid var(--line); }
.matcher-grid b { min-height: 38px; font: 600 16px/1.15 var(--serif); }
.matcher-grid select { width: 100%; padding: 10px; border: 1px solid var(--line); background: var(--white); font: 9px var(--mono); }
.matcher-grid select.correct { border-color: var(--green); background: rgba(106,165,135,.1); }
.matcher-grid select.incorrect, .matcher-grid select[aria-invalid="true"] { border-color: var(--red-deep); background: rgba(231,95,67,.08); }
.match-result { min-height: 1.5em; color: var(--muted); font: 500 10px/1.4 var(--mono); }
.matcher-icon { height: 80px; position: relative; display: block; background: var(--navy); overflow: hidden; }
.tube-icon::before { content:""; position:absolute; left:15%; right:10%; top:32px; height:16px; border:1px dashed var(--gold); }.tube-icon i { position:absolute; right:22%; top:29px; width:20px; height:20px; border:2px solid var(--red); border-radius:50%; }
.phase-icon::before { content:""; position:absolute; inset:20px; background:repeating-radial-gradient(ellipse at left,transparent 0 10px,rgba(118,167,197,.8) 11px 12px); }.phase-icon i { position:absolute; left:50%; top:10px; bottom:10px; width:2px; background:var(--red); }
.tensor-icon::before { content:""; position:absolute; inset:16px; background:linear-gradient(90deg,transparent 48%,rgba(255,255,255,.15) 50%,transparent 52%),linear-gradient(transparent 48%,rgba(255,255,255,.15) 50%,transparent 52%); background-size:20px 20px; }.tensor-icon i { position:absolute; inset:28px 48px; border:2px solid var(--red); }

.resonance-worked { display: grid; grid-template-columns: 1fr 1fr; margin: 25px 0 70px; border: 1px solid var(--line); }
.resonance-worked > div, .resonance-worked > p { padding: 25px; border-right: 1px solid var(--line); }
.resonance-worked > div:nth-child(2) { border-right: 0; }.resonance-worked > p { grid-column: 1/-1; margin: 0; border-top: 1px solid var(--line); border-right: 0; color: var(--muted); font-size: 10px; background: var(--paper-2); }
.resonance-worked .formula { margin-top: 12px; font-size: 10px; }
.roughness-lab canvas { width: 100%; height: 390px; background: var(--navy); }

.quiz-score { display: flex; justify-content: space-between; align-items: center; margin-bottom: 18px; padding: 14px 16px; color: white; background: var(--ink); font: 500 9px/1 var(--mono); }
.quiz-score button { color: white; border-color: rgba(255,255,255,.25); }
.quiz article.answered { background: rgba(16,29,44,.025); }
.quiz button:disabled { cursor: default; opacity: .72; }
.quiz button.correct::before { content: "✓ "; font-weight: 700; }
.quiz button.incorrect::before { content: "× "; font-weight: 700; }

.sources-section { padding: 140px 0; color: white; background: var(--navy); }
.sources-section .section-heading .lede { color: rgba(255,255,255,.5); }
.source-groups { display: grid; grid-template-columns: repeat(3,1fr); border-top: 1px solid rgba(255,255,255,.17); }
.source-groups > div { padding: 35px 28px 0 0; border-right: 1px solid rgba(255,255,255,.17); }
.source-groups > div:not(:first-child) { padding-left: 28px; }
.source-groups > div:last-child { border-right: 0; }
.source-groups h3 { min-height: 45px; color: rgba(255,255,255,.8); font: 500 11px/1.3 var(--mono); }
.source-groups h3 span { margin-right: 15px; color: var(--red); }
.source-groups a { display: block; min-height: 123px; padding: 20px 0; border-top: 1px solid rgba(255,255,255,.12); text-decoration: none; }
.source-groups a:hover span { color: white; }
.source-groups a b { display: block; margin-bottom: 7px; color: var(--red); font: 500 9px/1.4 var(--mono); }
.source-groups a span { display: block; color: rgba(255,255,255,.65); font: 600 12px/1.45 var(--sans); transition: color .2s; }
.source-groups a em { display: block; margin-top: 8px; color: rgba(255,255,255,.58); font: 400 10px/1.45 var(--mono); }
.citation-note { display: grid; grid-template-columns: .3fr 1fr .35fr; gap: 35px; margin-top: 75px; padding-top: 30px; border-top: 1px solid rgba(255,255,255,.17); }
.citation-note h3 { font: 600 20px/1 var(--serif); }
.citation-note p { color: rgba(255,255,255,.42); font-size: 10px; }
.citation-note p:last-child { font: 400 8px/1.5 var(--mono); }

footer { padding: 100px max(24px, calc((100vw - 1180px)/2)) 35px; color: white; background: #08111a; }
footer h2 { max-width: 900px; font-size: clamp(2.5rem, 5vw, 5rem); }
.footer-links { display: flex; gap: 28px; margin: 50px 0; }
.footer-links a { color: var(--red); font: 500 9px/1 var(--mono); }
.footer-small { margin: 0; padding-top: 25px; border-top: 1px solid rgba(255,255,255,.12); color: rgba(255,255,255,.3); font: 8px/1.5 var(--mono); }

@media (max-width: 1300px) {
  .chapter-rail { display: none; }
  .hero-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: clamp(4.3rem, 7vw, 6.5rem); }
}
@media (max-width: 980px) {
  :root { --content: min(100% - 32px, 760px); }
  .top-nav { display: none; }
  .nav-toggle { display: block; position: fixed; z-index: 75; top: 16px; right: 16px; border: 1px solid rgba(255,255,255,.25); background: rgba(16,29,44,.94); box-shadow: var(--shadow); }
  .chapter-rail { display: flex; top: 94px; left: auto; right: 16px; width: 220px; padding: 20px; transform: none; background: var(--white); box-shadow: var(--shadow); }
  .chapter-rail { max-height: calc(100dvh - 110px); overflow-y: auto; }
  .chapter-rail.visible { opacity: 1; }
  .chapter-rail a { width: 100%; color: var(--ink); }
  .chapter-rail p { margin-left: 0; }
  .hero-grid { grid-template-columns: 1fr; padding-top: 150px; }
  .hero-copy { padding-bottom: 0; }
  .hero-visual { min-height: 480px; }
  .hero-visual canvas { height: 480px; }
  .hero-foot { grid-template-columns: 1fr; padding: 22px 0; text-align: center; }
  .hero-foot p { margin: 0; }.hero-foot p:last-child { text-align: center; }
  .orientation-grid, .split-heading, .award-inner, .independence-explainer, .molecule-intro, .maxwellian-grid, .time-grid { grid-template-columns: 1fr; gap: 35px; }
  .pipeline { grid-template-columns: 1fr; }
  .pipeline-arrow { min-height: 110px; }.pipeline-arrow svg { width: 150px; margin: 12px auto; transform: rotate(90deg); }
  .pillars, .probability-grid, .related-pillars, .fluid-branches { grid-template-columns: 1fr; }
  .pillars article, .probability-grid article { border-right: 0; border-bottom: 1px solid rgba(255,255,255,.25); padding-left: 0 !important; }
  .definition-row { grid-template-columns: 1fr; }
  .collision-lab, .scaling-lab, .molecule-lab, .tree-lab { grid-template-columns: 1fr; }
  .hierarchy-heading, .wke-formula, .rough-field-box, .prior-regimes { grid-template-columns: 1fr; }
  .stage-note, .geometric-barrier, .budget-inner { grid-template-columns: 1fr; }
  .hierarchy-annotations, .entropy-steps, .frontier-grid { grid-template-columns: 1fr 1fr; }
  .rough-field-box > div:first-child { grid-column: 1 / -1; }
  .rough-thresholds { grid-column: 1 / -1; grid-template-columns: 1fr; }
  .resonance-lab { grid-template-columns: 1fr; }
  .credit-bridge { grid-template-columns: 1fr; }
  .credit-bridge > i { min-height: 45px; border: 0; border-top: 1px solid rgba(255,255,255,.12); border-bottom: 1px solid rgba(255,255,255,.12); }
  .frontier-grid article, .frontier-grid article:nth-child(3n) { border-right: 0; border-bottom: 0; }
  .frontier-grid article:nth-child(2n) { border-right: 1px solid var(--line); }
  .frontier-grid article:nth-last-child(-n+2) { border-bottom: 1px solid var(--line); }
  .scaling-readout { border: 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
  .proof-steps.horizontal { grid-template-columns: 1fr 1fr; }
  .theorem-box { grid-template-columns: 1fr; }
  .theorem-sidebar p { margin-top: 20px; }
  .proof-roadmap { grid-template-columns: 1fr; }
  .roadmap-nav { display: grid; grid-template-columns: repeat(4,1fr); border-right: 0; }
  .proof-tab { min-height: 70px; padding: 10px; }
  .invariant-key, .elementary-grid, .glossary-grid { grid-template-columns: 1fr 1fr; }
  .estimate-row { grid-template-columns: 1fr; gap: 0; }
  .math-operator { height: 45px; }
  .proof-close { grid-template-columns: 1fr; gap: 8px; }
  .proof-close > i { height: 30px; width: 1px; margin: auto; }
  .method-bridge { grid-template-columns: 1fr; }
  .method-specifics { grid-template-columns: 1fr; }
  .historical-branches { grid-template-columns: 1fr; }
  .historical-branches article { border-right: 1px solid var(--line); border-bottom: 0; }
  .historical-branches article:last-child { border-bottom: 1px solid var(--line); }
  .worked-bridge, .visual-quiz, .bbgky-contact-derivation, .duhamel-identification, .thin-target-example { grid-template-columns: 1fr; }
  .number-detail > div { grid-template-columns: 1fr; }
  .worked-bridge > div + div { border-left: 0; border-top: 1px solid var(--line); }
  .visual-quiz-copy { border-right: 0; border-bottom: 1px solid var(--line); }
  .chaos-quiz .visual-quiz-copy { border-color: rgba(255,255,255,.16); }
  .bbgky-contact-derivation > div { border-right: 0; border-bottom: 1px solid var(--line); }
  .bbgky-contact-derivation > div:last-child { border-bottom: 0; }
  .tree-count-flow { grid-template-columns: 1fr; gap: 8px; }
  .tree-count-flow i { transform: rotate(90deg); }
  .layer-choice-grid, .matcher-grid { grid-template-columns: 1fr; }
  .layer-choice-grid article, .matcher-grid label { border-right: 1px solid var(--line); border-bottom: 0; }
  .layer-choice-grid article:last-child, .matcher-grid label:last-child { border-bottom: 1px solid var(--line); }
  .entropy-number-example { grid-template-columns: 1fr; }
  .timeline { grid-template-columns: repeat(4,1fr); }
  .source-groups { grid-template-columns: 1fr; }
  .source-groups > div { padding: 30px 0 !important; border-right: 0; border-bottom: 1px solid rgba(255,255,255,.17); }
  .citation-note { grid-template-columns: 1fr; }
}
@media (max-width: 620px) {
  body { font-size: 14px; }
  h2 { font-size: 3.2rem; }
  .site-header { height: 75px; }
  .hero-grid { padding-top: 120px; }
  .hero h1 { font-size: 4rem; }
  .hero-actions, .hero-meta { flex-direction: column; }
  .hero-visual { min-height: 380px; }
  .hero-visual canvas { height: 380px; }
  .hero-equation { display: none; }
  #big-picture, #hard-spheres, #boltzmann, #proof, #lineage, #check { padding-top: 95px; padding-bottom: 95px; }
  .lab-toolbar { grid-template-columns: 1fr; }
  .scale-tab { min-height: 70px; border-right: 0; border-bottom: 1px solid var(--line); }
  .scale-stage, .scale-stage canvas { min-height: 400px; height: 400px; }
  .scale-explanation { grid-template-columns: 1fr; }
  .scale-explanation > div { border-right: 0; border-bottom: 1px solid var(--line); }
  .award-seal { display: none; }
  .award-inner { grid-template-columns: 1fr; }
  .award-copy blockquote { font-size: 2rem; }
  .equation-map { padding: 30px 15px; }
  .equation-main { gap: 8px; font-size: 1.2rem; }
  .collision-operator { flex-wrap: wrap; padding: 15px; }
  .proof-steps.horizontal { grid-template-columns: 1fr; }
  .proof-steps > li { grid-template-columns: 40px 1fr; }
  .derivation-title { grid-template-columns: 1fr 20px; }
  .derivation-title p { grid-column: 1 / -1; }
  .barrier-comparison { grid-template-columns: 1fr; }
  .versus { height: 60px; transform: rotate(90deg); }
  .theorem-content, .roadmap-content { padding: 28px 22px 80px; }
  .proof-roadmap { min-height: 800px; }
  .roadmap-nav { grid-template-columns: 1fr 1fr; }
  .proof-tab { font-size: 9px; }
  .invariant-key, .elementary-grid, .glossary-grid { grid-template-columns: 1fr; }
  .timeline { grid-template-columns: 1fr 1fr; }
  .timeline-detail { grid-template-columns: 1fr; }
  .timeline-detail .why { padding-left: 0; border-left: 0; }
  .dependency-map { overflow: auto; }
  .dependency-map svg { min-width: 780px; }
  .hierarchy-annotations, .entropy-steps, .method-specifics, .frontier-grid { grid-template-columns: 1fr; }
  .hierarchy-annotations article, .entropy-steps article { border-right: 1px solid var(--line); }
  .entropy-steps article { border-color: rgba(255,255,255,.13); border-bottom: 0; }
  .entropy-steps article:last-child { border-bottom: 1px solid rgba(255,255,255,.13); }
  .entropy-proof > div:first-child { display: block; }
  .budget-box, .precision-note { grid-template-columns: 1fr; }
  .dialect-table { overflow-x: auto; }
  .table-row { min-width: 720px; }
  .regime-grid { grid-template-columns: 1fr; }
  .regime-grid article, .regime-grid article:nth-child(2n) { border-right: 1px solid var(--line); border-bottom: 0; }
  .regime-grid article:last-child { border-bottom: 1px solid var(--line); }
  .frontier-grid article, .frontier-grid article:nth-child(2n), .frontier-grid article:nth-child(3n) { border-right: 1px solid var(--line); border-bottom: 0; }
  .frontier-grid article:last-child { border-bottom: 1px solid var(--line); }
  .search-box input { width: 190px; }
  .quiz article { grid-template-columns: 1fr; }
  .quiz-feedback { grid-column: 1; }
  .visual-quiz-copy, .visual-quiz-visual, .worked-bridge > div { padding: 23px 18px; }
  .density-controls, .cumulant-worked, .toy-recurrence, .resonance-worked { grid-template-columns: 1fr; }
  .cumulant-worked > p, .toy-recurrence p, .resonance-worked > p { grid-column: 1; }
  .resonance-worked > div { border-right: 0; border-bottom: 1px solid var(--line); }
  .duhamel-visual { grid-template-columns: 1fr; gap: 15px; }
  .duhamel-visual > i { transform: rotate(90deg); }
  .ledger-bars > div, .budget-race > div { grid-template-columns: 110px 1fr 55px; }
  .quiz-score { align-items: flex-start; gap: 15px; }
  .motion-toggle { right: 12px; bottom: 12px; font-size: 9px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}