:root {
  --paper: #f4f0e8;
  --paper-deep: #ebe5d9;
  --paper-light: #efe9dd;
  --ink: #141412;
  --muted: #6e6a61;
  --line: #c9c1b4;
  --line-dark: #8f897f;
  --accent: #bb3f24;
  --accent-dark: #7f2818;
  --accent-soft: #e9c5b8;
  --accent-pale: #f2ddd5;
  --sage: #9aa692;
  --sage-pale: #dfe5dc;
  --blue-gray: #7f9296;
  --blue-pale: #dce5e5;
  --warning: #d69d3d;
  --shadow: 0 22px 70px rgba(27, 24, 18, 0.09);
  --serif: Georgia, "Times New Roman", Times, serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --content: 700px;
  --wide: 1020px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.68;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 0.16em; }
a:hover { color: var(--accent); }
button, input, output { font: inherit; }
button { color: inherit; }
svg { max-width: 100%; }

.skip-link {
  position: fixed;
  left: 16px;
  top: -60px;
  z-index: 1000;
  background: var(--ink);
  color: var(--paper);
  padding: 10px 14px;
  font: 700 13px/1 var(--sans);
  transition: top .2s ease;
}
.skip-link:focus { top: 16px; }

.reading-progress {
  position: fixed;
  inset: 0 0 auto 0;
  height: 3px;
  z-index: 999;
  pointer-events: none;
}
.reading-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--accent);
  transform-origin: left center;
}

.site-header {
  max-width: 1280px;
  margin: 0 auto;
  padding: 26px 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
  font-family: var(--sans);
}
.wordmark {
  display: inline-flex;
  gap: 12px;
  align-items: center;
  text-decoration: none;
  font-size: 15px;
  font-weight: 720;
  letter-spacing: .02em;
}
.wordmark-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 1.5px solid var(--ink);
  font: 800 11px/1 var(--sans);
  letter-spacing: .04em;
}
.site-nav { display: flex; gap: 24px; align-items: center; font-size: 13px; }
.site-nav a { text-decoration: none; }
.text-button {
  appearance: none;
  border: 0;
  background: none;
  padding: 0;
  cursor: pointer;
  font: inherit;
}
.text-button:hover, .text-button:focus-visible { color: var(--accent); }

.article-hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 104px 36px 56px;
}
.eyebrow {
  font: 700 11px/1.2 var(--sans);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--accent);
}
.article-hero h1 {
  margin: 24px 0 26px;
  max-width: 1080px;
  font-size: clamp(50px, 6.6vw, 88px);
  line-height: .9;
  letter-spacing: -.058em;
  font-weight: 500;
}
.article-hero h1 .line-two { display: block; }
.dek {
  max-width: 850px;
  margin: 0;
  font-size: clamp(24px, 2.5vw, 38px);
  line-height: 1.22;
  letter-spacing: -.025em;
  color: #35322d;
}
.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 11px;
  margin-top: 34px;
  font: 600 12px/1 var(--sans);
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--muted);
}

.hero-system {
  margin: 80px 0 0;
  padding: 34px;
  background: var(--paper-light);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}
.hero-system svg { display: block; width: 100%; height: auto; }
.hero-system figcaption {
  margin-top: 18px;
  border: 0;
  padding: 0;
  font: 500 13px/1.5 var(--sans);
  color: var(--muted);
}
.hero-system .frame { fill: none; stroke: var(--line-dark); stroke-width: 1.3; }
.hero-system .frame-soft { fill: none; stroke: var(--line); stroke-width: 1; }
.hero-system .cable { fill: none; stroke: var(--accent); stroke-width: 1.7; }
.hero-system .cable-muted { fill: none; stroke: var(--blue-gray); stroke-width: 1.4; stroke-dasharray: 7 7; }
.hero-system .node { fill: var(--paper); stroke: var(--ink); stroke-width: 1.4; }
.hero-system .motor { fill: var(--ink); }
.hero-system .human { fill: none; stroke: var(--ink); stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.hero-system .safety { fill: var(--accent-pale); stroke: var(--accent); stroke-width: 1; }
.hero-system .floor { fill: var(--sage-pale); stroke: var(--sage); stroke-width: 1; }
.hero-system .mono { font: 700 13px/1 var(--mono); letter-spacing: .08em; }
.hero-system .tiny { font: 650 11px/1 var(--sans); letter-spacing: .1em; }
.hero-system .label { font: 650 14px/1 var(--sans); }
.hero-system .title { font: 400 26px/1 var(--serif); }
.hero-system .force-dot { fill: var(--accent); }

.article-layout {
  max-width: 1140px;
  margin: 70px auto 0;
  padding: 0 36px 110px;
  display: grid;
  grid-template-columns: 190px minmax(0, var(--content));
  gap: 72px;
  justify-content: center;
}
.article-rail { position: relative; }
.rail-inner {
  position: sticky;
  top: 40px;
  padding-top: 8px;
  font-family: var(--sans);
}
.rail-label {
  padding-bottom: 12px;
  border-bottom: 1px solid var(--ink);
  font: 750 12px/1.35 var(--sans);
  letter-spacing: .13em;
  text-transform: uppercase;
}
.toc { display: grid; margin-top: 14px; }
.toc a {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 6px;
  padding: 7px 0;
  color: var(--muted);
  text-decoration: none;
  font: 500 12px/1.35 var(--sans);
  transition: color .15s ease, transform .15s ease;
}
.toc a span { font: 700 10px/1.5 var(--mono); color: var(--line-dark); }
.toc a:hover, .toc a.active { color: var(--ink); transform: translateX(3px); }
.toc a.active span { color: var(--accent); }
.rail-note {
  margin-top: 24px;
  color: var(--muted);
  font: 500 11px/1.55 var(--sans);
}

.article-body { min-width: 0; }
.article-body p { margin: 0 0 1.35em; }
.article-body strong { font-weight: 700; }
.lede {
  margin: 0 0 1.2em;
  font-size: 31px;
  line-height: 1.32;
  letter-spacing: -.022em;
}
.citation {
  font: 700 10px var(--sans);
  vertical-align: super;
  text-decoration: none;
  color: var(--accent);
  margin-left: 1px;
}

.article-section {
  position: relative;
  padding-top: 100px;
  scroll-margin-top: 20px;
}
.section-number {
  position: absolute;
  left: -82px;
  top: 109px;
  font: 700 11px/1 var(--sans);
  color: var(--accent);
  letter-spacing: .13em;
}
.article-section h2 {
  margin: 0 0 34px;
  font-size: 50px;
  line-height: 1.02;
  letter-spacing: -.045em;
  font-weight: 500;
}
.article-section h3 {
  margin: 46px 0 16px;
  font-family: var(--serif);
  font-weight: 600;
}

blockquote {
  margin: 68px -110px;
  padding: 0 0 0 42px;
  border-left: 4px solid var(--accent);
  font-size: 40px;
  line-height: 1.2;
  letter-spacing: -.035em;
}
blockquote p { margin: 0 !important; }
blockquote cite {
  display: block;
  margin-top: 16px;
  font: 700 11px/1.4 var(--sans);
  font-style: normal;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--muted);
}

.wide-figure,
.timeline-figure,
.stack-figure,
.financial-figure,
.frozen-figure,
.machine-figure,
.control-figure,
.bootstrap-figure,
.arcade-figure,
.health-figure,
.failure-figure,
.safety-explorer,
.truth-box {
  width: min(var(--wide), calc(100vw - 72px));
  margin: 68px 0 68px 50%;
  transform: translateX(-50%);
  background: var(--paper-light);
  border: 1px solid var(--line);
}
.figure-inner { padding: 30px; }
figcaption, .figure-caption {
  border-top: 1px solid var(--line);
  padding: 15px 20px;
  color: var(--muted);
  font: 500 13px/1.5 var(--sans);
}
.figure-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line);
}
.figure-header h3 {
  margin: 0 0 6px;
  font: 700 16px/1.2 var(--sans);
  letter-spacing: -.01em;
}
.figure-header p {
  margin: 0;
  max-width: 720px;
  font: 500 13px/1.5 var(--sans);
  color: var(--muted);
}
.figure-badge {
  flex: none;
  padding: 6px 9px;
  border: 1px solid var(--line-dark);
  font: 700 9px/1 var(--sans);
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--muted);
}

.timeline-wrap { padding: 30px 30px 26px; overflow: hidden; }
.timeline-track {
  position: relative;
  display: grid;
  grid-template-columns: repeat(7, minmax(126px, 1fr));
  gap: 14px;
  padding-top: 34px;
}
.timeline-track::before {
  content: "";
  position: absolute;
  top: 14px;
  left: 2%;
  right: 2%;
  height: 1px;
  background: var(--line-dark);
}
.timeline-event { position: relative; }
.timeline-event::before {
  content: "";
  position: absolute;
  top: -25px;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  border: 2px solid var(--paper-light);
  background: var(--accent);
  box-shadow: 0 0 0 1px var(--accent);
}
.timeline-year {
  display: block;
  margin-bottom: 8px;
  color: var(--accent);
  font: 700 12px/1 var(--mono);
}
.timeline-event h4 {
  margin: 0 0 7px;
  font: 700 14px/1.25 var(--sans);
}
.timeline-event p {
  margin: 0;
  color: var(--muted);
  font: 500 12px/1.45 var(--sans);
}
.timeline-wave {
  margin-top: 28px;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  border: 1px solid var(--line);
}
.timeline-wave > div { padding: 14px; border-right: 1px solid var(--line); }
.timeline-wave > div:last-child { border-right: 0; }
.timeline-wave span {
  display: block;
  font: 700 10px/1 var(--sans);
  text-transform: uppercase;
  letter-spacing: .11em;
  color: var(--muted);
}
.timeline-wave strong { font: 500 16px/1.35 var(--serif); }

.stack-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line);
}
.stack-column { background: var(--paper-light); padding: 30px; }
.stack-column h3 { margin: 0 0 6px; font: 700 16px/1.2 var(--sans); }
.stack-column > p { color: var(--muted); font: 500 13px/1.5 var(--sans); }
.stack-layers { margin-top: 23px; display: grid; gap: 9px; }
.stack-layer {
  display: grid;
  grid-template-columns: 34px 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 12px;
  border: 1px solid var(--line);
  background: var(--paper);
}
.stack-layer .icon {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid var(--line-dark);
  font: 700 10px/1 var(--mono);
}
.stack-layer strong { font: 700 13px/1.2 var(--sans); }
.stack-layer small { color: var(--muted); font: 600 10px/1.2 var(--sans); text-transform: uppercase; letter-spacing: .06em; }
.stack-column.visual .stack-layer:nth-child(-n+4) { border-color: var(--sage); background: var(--sage-pale); }
.stack-column.physical .stack-layer:nth-child(n+4) { border-style: dashed; }
.stack-state {
  margin-top: 20px;
  padding: 13px 15px;
  font: 700 13px/1.4 var(--sans);
  border-left: 4px solid var(--accent);
  background: var(--accent-pale);
}

.financial-wrap { padding: 30px; }
.chart-key { display: flex; flex-wrap: wrap; gap: 18px; margin: 0 0 18px; }
.key-item { display: inline-flex; align-items: center; gap: 7px; font: 650 11px/1 var(--sans); color: var(--muted); }
.key-swatch { width: 20px; height: 3px; background: var(--ink); }
.key-swatch.loss { background: var(--accent); }
.financial-chart { width: 100%; height: auto; display: block; }
.financial-chart text { font-family: var(--sans); }
.financial-chart .grid { stroke: var(--line); stroke-width: 1; }
.financial-chart .axis-label { fill: var(--muted); font-size: 11px; }
.financial-chart .year { fill: var(--ink); font-size: 12px; font-weight: 700; }
.financial-chart .bar-revenue { fill: var(--ink); }
.financial-chart .bar-loss { fill: var(--accent); }
.financial-chart .value { fill: var(--ink); font-size: 11px; font-weight: 700; }
.financial-chart .value-loss { fill: var(--accent-dark); font-size: 11px; font-weight: 700; }
.chart-note {
  margin-top: 17px;
  color: var(--muted);
  font: 500 12px/1.55 var(--sans);
}

.arcade-history {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
}
.arcade-era { background: var(--paper-light); padding: 28px; min-height: 262px; }
.arcade-era .era-label { color: var(--accent); font: 700 10px/1 var(--mono); letter-spacing: .1em; }
.arcade-era h4 { margin: 16px 0 10px; font: 500 25px/1.06 var(--serif); }
.arcade-era p { margin: 0; color: var(--muted); font: 500 13px/1.55 var(--sans); }
.arcade-era .scarcity {
  display: inline-block;
  margin-top: 18px;
  border-top: 1px solid var(--line-dark);
  padding-top: 9px;
  font: 700 11px/1.4 var(--sans);
}

.frozen-grid {
  display: grid;
  grid-template-columns: 1.12fr .88fr;
  gap: 1px;
  background: var(--line);
}
.machine-room, .compiler-room { background: var(--paper-light); padding: 30px; }
.room-title { margin-bottom: 18px; font: 700 12px/1 var(--sans); letter-spacing: .08em; text-transform: uppercase; }
.machine-icons { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.machine-icon {
  min-height: 118px;
  border: 1px solid var(--line);
  padding: 13px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: var(--paper);
}
.machine-icon svg { width: 100%; height: 55px; }
.machine-icon span { font: 700 10px/1.2 var(--sans); text-transform: uppercase; letter-spacing: .06em; }
.compiler-diagram { display: grid; gap: 12px; }
.code-card {
  border: 1px solid var(--line-dark);
  padding: 15px;
  background: var(--ink);
  color: var(--paper);
  font: 500 12px/1.55 var(--mono);
}
.compile-arrow { text-align: center; font: 700 18px/1 var(--sans); color: var(--accent); }
.force-primitives { display: flex; flex-wrap: wrap; gap: 7px; }
.force-primitives span { border: 1px solid var(--line-dark); padding: 7px 9px; font: 700 10px/1 var(--sans); text-transform: uppercase; letter-spacing: .05em; }

.truth-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); }
.truth-column { background: var(--paper-light); padding: 28px; }
.truth-column h3 { margin: 0 0 20px; font: 700 13px/1 var(--sans); text-transform: uppercase; letter-spacing: .09em; }
.truth-column ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 14px; }
.truth-column li { position: relative; padding-left: 18px; color: var(--muted); font: 500 13px/1.5 var(--sans); }
.truth-column li::before { content: ""; position: absolute; left: 0; top: .63em; width: 7px; height: 7px; background: var(--accent); }
.truth-column.unsolved li::before { background: var(--warning); }
.truth-column.not-claimed li::before { background: var(--line-dark); }

.machine-cutaway { padding: 18px; }
.machine-cutaway svg { display: block; width: 100%; height: auto; }
.machine-cutaway text { font-family: var(--sans); }
.machine-cutaway .shell { fill: none; stroke: var(--line-dark); stroke-width: 1.5; }
.machine-cutaway .shell-soft { fill: none; stroke: var(--line); stroke-width: 1; stroke-dasharray: 7 7; }
.machine-cutaway .cable { stroke: var(--accent); stroke-width: 1.7; fill: none; }
.machine-cutaway .cable-secondary { stroke: var(--blue-gray); stroke-width: 1.4; fill: none; }
.machine-cutaway .motor { fill: var(--ink); }
.machine-cutaway .platform { fill: var(--sage-pale); stroke: var(--sage); }
.machine-cutaway .human { fill: none; stroke: var(--ink); stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.machine-cutaway .callout { fill: var(--paper); stroke: var(--line-dark); }
.machine-cutaway .callout-text { fill: var(--ink); font-size: 12px; font-weight: 700; }
.machine-cutaway .callout-sub { fill: var(--muted); font-size: 10px; }
.machine-cutaway .leader { stroke: var(--line-dark); stroke-width: 1; fill: none; }
.machine-cutaway .danger { fill: var(--accent-pale); stroke: var(--accent); }

.primitives-table { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--line); }
.primitive { background: var(--paper-light); padding: 22px; min-height: 145px; }
.primitive code { display: block; color: var(--accent); margin-bottom: 12px; font: 700 12px/1 var(--mono); }
.primitive h4 { margin: 0 0 8px; font: 700 14px/1.25 var(--sans); }
.primitive p { margin: 0; color: var(--muted); font: 500 12px/1.5 var(--sans); }

.body-account {
  display: grid;
  grid-template-columns: 1fr 90px 1fr;
  align-items: center;
  gap: 18px;
  padding: 34px;
}
.body-card { border: 1px solid var(--line-dark); padding: 22px; background: var(--paper); }
.body-card h4 { margin: 0 0 14px; font: 700 14px/1.2 var(--sans); }
.body-metrics { display: grid; gap: 8px; }
.body-metric { display: grid; grid-template-columns: 1fr auto; gap: 10px; padding-bottom: 7px; border-bottom: 1px solid var(--line); font: 600 11px/1.2 var(--sans); }
.body-metric span:last-child { font-family: var(--mono); color: var(--accent); }
.body-arrow { text-align: center; font: 700 24px/1 var(--sans); color: var(--accent); }
.world-card { display: grid; gap: 10px; }
.world-object { border: 1px solid var(--line); padding: 12px; background: var(--paper); font: 700 12px/1.25 var(--sans); }
.world-object small { display: block; color: var(--muted); margin-top: 4px; font-weight: 500; }

.control-stack { display: grid; gap: 0; padding: 30px; }
.control-layer {
  position: relative;
  display: grid;
  grid-template-columns: 170px 1fr;
  gap: 25px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-bottom: 0;
  background: var(--paper);
}
.control-layer:last-child { border-bottom: 1px solid var(--line); }
.control-layer .layer-name { font: 700 12px/1.3 var(--sans); text-transform: uppercase; letter-spacing: .06em; }
.control-layer p { margin: 0; color: var(--muted); font: 500 13px/1.5 var(--sans); }
.control-layer.policy { background: var(--blue-pale); }
.control-layer.safety { background: var(--accent-pale); border-color: var(--accent); }
.control-layer.hardware { background: var(--sage-pale); }
.control-layer .authority {
  position: absolute;
  right: 12px;
  top: 11px;
  font: 700 9px/1 var(--mono);
  text-transform: uppercase;
  color: var(--muted);
}
.safety-rules { margin-top: 24px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.safety-rule { padding: 14px; border: 1px solid var(--line); background: var(--paper); }
.safety-rule strong { display: block; margin-bottom: 6px; font: 700 11px/1.2 var(--sans); text-transform: uppercase; letter-spacing: .05em; }
.safety-rule span { color: var(--muted); font: 500 11px/1.45 var(--sans); }

.safety-explorer { overflow: hidden; }
.explorer-shell { display: grid; grid-template-columns: 340px 1fr; min-height: 520px; }
.explorer-controls { padding: 30px; border-right: 1px solid var(--line); background: var(--paper-light); }
.explorer-controls h3 { margin: 0 0 8px; font: 700 16px/1.2 var(--sans); }
.explorer-controls > p { color: var(--muted); font: 500 13px/1.5 var(--sans); }
.control-list { margin-top: 25px; display: grid; gap: 21px; }
.range-field { display: grid; gap: 9px; }
.range-label { display: flex; justify-content: space-between; align-items: baseline; gap: 15px; font: 650 12px/1.3 var(--sans); }
.range-label output { color: var(--accent); font: 700 12px/1 var(--mono); }
input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}
.range-hint { color: var(--muted); font: 500 10px/1.35 var(--sans); }
.explorer-view { padding: 30px; display: flex; flex-direction: column; background: var(--paper); }
.explorer-status { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-bottom: 22px; }
.status-card { padding: 13px; border: 1px solid var(--line); background: var(--paper-light); }
.status-card span { display: block; color: var(--muted); font: 650 9px/1 var(--sans); text-transform: uppercase; letter-spacing: .08em; }
.status-card strong { display: block; margin-top: 7px; font: 500 24px/1 var(--serif); }
.status-card.mode strong { font: 750 15px/1.2 var(--sans); color: var(--accent); }
.force-meter { position: relative; flex: 1; min-height: 260px; border-left: 1px solid var(--line-dark); border-bottom: 1px solid var(--line-dark); padding: 22px 20px 30px 55px; }
.force-grid { position: absolute; inset: 20px 20px 30px 55px; display: grid; grid-template-rows: repeat(4, 1fr); }
.force-grid i { border-top: 1px solid var(--line); }
.force-grid-labels { position: absolute; left: 0; top: 13px; bottom: 23px; width: 48px; display: flex; flex-direction: column; justify-content: space-between; color: var(--muted); font: 600 9px/1 var(--mono); text-align: right; }
.bars { position: absolute; inset: 20px 20px 30px 55px; display: flex; align-items: flex-end; justify-content: center; gap: 55px; }
.force-bar-wrap { width: 95px; height: 100%; display: flex; align-items: flex-end; justify-content: center; position: relative; }
.force-bar { width: 68px; min-height: 2px; transition: height .35s ease; }
.force-bar.requested { background: var(--ink); }
.force-bar.allowed { background: var(--accent); }
.bar-label { position: absolute; bottom: -24px; width: 130px; text-align: center; font: 700 10px/1 var(--sans); text-transform: uppercase; letter-spacing: .05em; }
.bar-value { position: absolute; transform: translateY(-8px); font: 700 11px/1 var(--mono); white-space: nowrap; }
.envelope-line { position: absolute; left: 55px; right: 20px; height: 0; border-top: 2px dashed var(--warning); transition: bottom .35s ease; }
.envelope-line span { position: absolute; right: 0; bottom: 6px; color: #8e6319; font: 700 9px/1 var(--sans); text-transform: uppercase; letter-spacing: .05em; background: var(--paper); padding-left: 5px; }
.explorer-explanation { margin-top: 18px; padding: 14px 16px; border-left: 4px solid var(--accent); background: var(--accent-pale); font: 600 12px/1.5 var(--sans); }

.bootstrap-path { padding: 30px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; }
.stage-card { position: relative; padding: 24px 18px; border: 1px solid var(--line); border-right: 0; background: var(--paper); min-height: 260px; }
.stage-card:last-child { border-right: 1px solid var(--line); }
.stage-card::after {
  content: "";
  position: absolute;
  z-index: 2;
  right: -9px;
  top: 45px;
  width: 16px;
  height: 16px;
  border-top: 1px solid var(--line-dark);
  border-right: 1px solid var(--line-dark);
  background: var(--paper);
  transform: rotate(45deg);
}
.stage-card:last-child::after { display: none; }
.stage-number { color: var(--accent); font: 700 11px/1 var(--mono); }
.stage-card h4 { margin: 17px 0 10px; font: 500 23px/1.08 var(--serif); }
.stage-card p { margin: 0; color: var(--muted); font: 500 12px/1.5 var(--sans); }
.stage-proof { position: absolute; left: 18px; right: 18px; bottom: 20px; padding-top: 11px; border-top: 1px solid var(--line); font: 700 10px/1.35 var(--sans); text-transform: uppercase; letter-spacing: .05em; }

.why-gym-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); }
.why-card { background: var(--paper-light); padding: 24px; min-height: 180px; }
.why-card .why-num { color: var(--accent); font: 700 10px/1 var(--mono); }
.why-card h4 { margin: 15px 0 8px; font: 700 14px/1.25 var(--sans); }
.why-card p { margin: 0; color: var(--muted); font: 500 12px/1.5 var(--sans); }

.arcade-return { padding: 30px; }
.arcade-equation {
  display: grid;
  grid-template-columns: 1fr 80px 1fr;
  align-items: center;
  gap: 24px;
}
.equation-card { border: 1px solid var(--line-dark); padding: 24px; background: var(--paper); min-height: 240px; }
.equation-card .eq-era { color: var(--accent); font: 700 10px/1 var(--mono); text-transform: uppercase; letter-spacing: .08em; }
.equation-card h4 { margin: 16px 0 14px; font: 500 26px/1.1 var(--serif); }
.equation-card ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 9px; }
.equation-card li { padding-left: 15px; position: relative; color: var(--muted); font: 500 12px/1.45 var(--sans); }
.equation-card li::before { content: ""; position: absolute; left: 0; top: .62em; width: 5px; height: 5px; background: var(--accent); }
.eq-arrow { text-align: center; font: 700 28px/1 var(--sans); color: var(--accent); }
.arcade-line { margin-top: 28px; padding: 23px; border-top: 1px solid var(--line-dark); border-bottom: 1px solid var(--line-dark); font-size: 25px; line-height: 1.35; text-align: center; }

.health-loop { padding: 34px; }
.loop-row { display: grid; grid-template-columns: repeat(5, 1fr); align-items: center; gap: 8px; }
.loop-node { min-height: 130px; display: grid; place-items: center; align-content: center; text-align: center; border: 1px solid var(--line); background: var(--paper); padding: 16px; }
.loop-node strong { font: 700 12px/1.25 var(--sans); }
.loop-node span { margin-top: 6px; color: var(--muted); font: 500 10px/1.35 var(--sans); }
.loop-arrow { text-align: center; color: var(--accent); font: 700 18px/1 var(--sans); }
.health-caveat { margin-top: 20px; color: var(--muted); font: 500 12px/1.55 var(--sans); }

.failure-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); }
.failure-card { background: var(--paper-light); padding: 25px; min-height: 225px; }
.failure-card .risk { color: var(--accent); font: 700 10px/1 var(--mono); text-transform: uppercase; letter-spacing: .07em; }
.failure-card h4 { margin: 14px 0 9px; font: 700 14px/1.25 var(--sans); }
.failure-card p { margin: 0; color: var(--muted); font: 500 12px/1.5 var(--sans); }
.failure-card .test { display: block; margin-top: 16px; padding-top: 11px; border-top: 1px solid var(--line); font: 700 10px/1.4 var(--sans); text-transform: uppercase; letter-spacing: .05em; }

.old-new { margin: 52px -70px; border: 1px solid var(--ink); }
.old-new > div { padding: 30px; }
.old-new > div + div { border-top: 1px solid var(--ink); }
.old-new .new-sequence { background: var(--accent); color: var(--paper); }
.old-new-label { margin-bottom: 14px; font: 800 10px var(--sans); text-transform: uppercase; letter-spacing: .13em; color: var(--muted); }
.new-sequence .old-new-label { color: var(--accent-pale); }
.old-new p { margin: 0 !important; font-size: 25px; line-height: 1.35; }
.closing-line {
  margin: 70px -80px 0 !important;
  padding: 70px 80px;
  background: var(--ink);
  color: var(--paper);
  font-size: 52px;
  line-height: 1.05;
  letter-spacing: -.045em;
  text-align: center;
}

.sources {
  margin-top: 70px;
  padding-top: 40px;
  border-top: 2px solid var(--ink);
  font-family: var(--sans);
  scroll-margin-top: 20px;
}
.sources h2 { margin: 0 0 25px; font-size: 20px; letter-spacing: -.02em; }
.sources ol { margin: 0; padding-left: 22px; }
.sources li { padding: 13px 0; border-bottom: 1px solid var(--line); font-size: 12px; line-height: 1.5; color: var(--muted); }
.sources li::marker { color: var(--accent); font-weight: 800; }
.sources li a { display: inline-block; margin-left: 8px; font-weight: 700; text-decoration: none; color: var(--ink); }
.methods-note { margin-top: 24px !important; padding: 18px; background: var(--paper-deep); font-size: 11px; line-height: 1.55; color: var(--muted); }

.site-footer {
  max-width: 1280px;
  margin: 110px auto 0;
  padding: 42px 36px 65px;
  border-top: 1px solid var(--ink);
  display: flex;
  justify-content: space-between;
  gap: 50px;
  font-family: var(--sans);
}
.site-footer p { max-width: 430px; margin: 15px 0 0; font-size: 12px; color: var(--muted); }
.footer-contact { display: flex; flex-direction: column; align-items: flex-end; gap: 6px; font-size: 12px; }
.footer-contact span, .footer-contact small { color: var(--muted); }
.footer-contact a { text-decoration: none; font-weight: 700; }
.footer-wordmark { font-size: 14px; }

.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translate(-50%, 20px);
  padding: 10px 15px;
  background: var(--ink);
  color: var(--paper);
  opacity: 0;
  pointer-events: none;
  font: 700 12px var(--sans);
  transition: opacity .2s ease, transform .2s ease;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

.reveal { opacity: 1; transition: opacity .55s ease, transform .55s ease; }
.has-js .reveal { opacity: 0; transform: translateY(18px); }
.has-js .reveal.is-visible { opacity: 1; transform: translateY(0); }
.has-js .wide-figure.reveal.is-visible,
.has-js .timeline-figure.reveal.is-visible,
.has-js .stack-figure.reveal.is-visible,
.has-js .financial-figure.reveal.is-visible,
.has-js .frozen-figure.reveal.is-visible,
.has-js .machine-figure.reveal.is-visible,
.has-js .control-figure.reveal.is-visible,
.has-js .bootstrap-figure.reveal.is-visible,
.has-js .arcade-figure.reveal.is-visible,
.has-js .health-figure.reveal.is-visible,
.has-js .failure-figure.reveal.is-visible,
.has-js .safety-explorer.reveal.is-visible,
.has-js .truth-box.reveal.is-visible { transform: translateX(-50%) translateY(0); }
.has-js .wide-figure.reveal,
.has-js .timeline-figure.reveal,
.has-js .stack-figure.reveal,
.has-js .financial-figure.reveal,
.has-js .frozen-figure.reveal,
.has-js .machine-figure.reveal,
.has-js .control-figure.reveal,
.has-js .bootstrap-figure.reveal,
.has-js .arcade-figure.reveal,
.has-js .health-figure.reveal,
.has-js .failure-figure.reveal,
.has-js .safety-explorer.reveal,
.has-js .truth-box.reveal { transform: translateX(-50%) translateY(18px); }

@media (max-width: 1040px) {
  .article-layout { grid-template-columns: minmax(0, var(--content)); padding-left: 28px; padding-right: 28px; }
  .article-rail { display: none; }
  .section-number { position: static; margin-bottom: 14px; }
  blockquote { margin-left: 0; margin-right: 0; }
  .old-new { margin-left: 0; margin-right: 0; }
  .closing-line { margin-left: 0 !important; margin-right: 0 !important; padding: 58px 40px; }
  .wide-figure,
  .timeline-figure,
  .stack-figure,
  .financial-figure,
  .frozen-figure,
  .machine-figure,
  .control-figure,
  .bootstrap-figure,
  .arcade-figure,
  .health-figure,
  .failure-figure,
  .safety-explorer,
  .truth-box { width: min(1000px, calc(100vw - 40px)); }
}

@media (max-width: 780px) {
  body { font-size: 17px; }
  .site-header { padding: 18px 20px; }
  .site-nav { gap: 14px; }
  .site-nav a { display: none; }
  .article-hero { padding: 70px 20px 30px; }
  .article-hero h1 { font-size: clamp(42px, 10.5vw, 68px); letter-spacing: -.05em; }
  .dek { font-size: 23px; }
  .hero-system { margin-top: 50px; padding: 15px; }
  .article-layout { margin-top: 40px; padding: 0 20px 90px; }
  .lede { font-size: 26px; }
  .article-section h2 { font-size: 40px; }
  blockquote { padding-left: 24px; font-size: 31px; }
  .figure-inner, .timeline-wrap, .financial-wrap, .arcade-return, .health-loop { padding: 20px; }
  .figure-header { padding-bottom: 16px; margin-bottom: 22px; }
  .timeline-track { overflow-x: auto; grid-template-columns: repeat(7, 145px); padding-bottom: 12px; }
  .timeline-track::before { right: auto; width: 1030px; }
  .timeline-wave { grid-template-columns: 1fr; }
  .timeline-wave > div { border-right: 0; border-bottom: 1px solid var(--line); }
  .timeline-wave > div:last-child { border-bottom: 0; }
  .stack-grid, .frozen-grid, .truth-grid { grid-template-columns: 1fr; }
  .arcade-history, .failure-grid { grid-template-columns: 1fr; }
  .primitives-table { grid-template-columns: 1fr 1fr; }
  .body-account { grid-template-columns: 1fr; }
  .body-arrow { transform: rotate(90deg); }
  .control-layer { grid-template-columns: 1fr; gap: 8px; }
  .safety-rules, .why-gym-grid { grid-template-columns: 1fr 1fr; }
  .explorer-shell { grid-template-columns: 1fr; }
  .explorer-controls { border-right: 0; border-bottom: 1px solid var(--line); }
  .bootstrap-path { grid-template-columns: 1fr; }
  .stage-card { border-right: 1px solid var(--line); border-bottom: 0; min-height: 220px; }
  .stage-card:last-child { border-bottom: 1px solid var(--line); }
  .stage-card::after { display: none; }
  .arcade-equation { grid-template-columns: 1fr; }
  .eq-arrow { transform: rotate(90deg); }
  .loop-row { grid-template-columns: 1fr; }
  .loop-arrow { transform: rotate(90deg); }
  .old-new > div { padding: 22px; }
  .old-new p { font-size: 21px; }
  .closing-line { padding: 55px 24px; font-size: 38px; }
  .site-footer { margin-top: 70px; padding: 34px 20px 50px; flex-direction: column; }
  .footer-contact { align-items: flex-start; }
}

@media (max-width: 520px) {
  .article-hero h1 { font-size: 40px; letter-spacing: -.04em; }
  .dek { font-size: 21px; }
  .article-meta { gap: 5px; }
  .figure-header { flex-direction: column; }
  .machine-icons { grid-template-columns: 1fr 1fr; }
  .primitives-table, .safety-rules, .why-gym-grid { grid-template-columns: 1fr; }
  .explorer-status { grid-template-columns: 1fr; }
  .bars { gap: 24px; }
  .force-bar-wrap { width: 80px; }
  .force-bar { width: 52px; }
  .closing-line { font-size: 31px; }
}

@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, .has-js .reveal { opacity: 1; transform: none !important; }
}

@media print {
  :root { --paper: #fff; --paper-deep: #f2f2f2; --paper-light: #f7f7f7; --ink: #000; --muted: #444; --line: #bbb; }
  @page { size: A4; margin: 18mm 16mm 20mm; }
  body { font-size: 11pt; line-height: 1.5; background: #fff; }
  .site-header, .reading-progress, .article-rail, .site-footer, .toast, .site-nav, .safety-explorer { display: none !important; }
  .article-hero { padding: 0 0 12mm; }
  .article-hero h1 { font-size: 44pt; }
  .dek { font-size: 17pt; }
  .hero-system { box-shadow: none; break-inside: avoid; }
  .article-layout { display: block; max-width: none; margin: 0; padding: 0; }
  .article-body { max-width: none; }
  .article-section { padding-top: 14mm; }
  .article-section h2 { font-size: 27pt; }
  .section-number { position: static; margin-bottom: 4mm; }
  blockquote { margin: 10mm 0; font-size: 20pt; }
  .wide-figure, .timeline-figure, .stack-figure, .financial-figure, .frozen-figure, .machine-figure, .control-figure, .bootstrap-figure, .arcade-figure, .health-figure, .failure-figure, .truth-box {
    width: 100%; margin: 10mm 0; transform: none !important; box-shadow: none; break-inside: avoid;
  }
  .reveal, .has-js .reveal { opacity: 1; transform: none !important; }
  .old-new { margin: 10mm 0; }
  .closing-line { margin: 10mm 0 0 !important; padding: 10mm; font-size: 24pt; }
  a { text-decoration: none; }
  .sources a::after { content: " (" attr(href) ")"; font-weight: 400; word-break: break-all; }
}