:root {
  color-scheme: dark;
  --ink: #071514;
  --ink-soft: #102422;
  --paper: #edf3e8;
  --paper-soft: #dfe9dc;
  --lime: #c8ff51;
  --cyan: #73e8f3;
  --copper: #cf6c3d;
  --copper-dark: #7c321f;
  --white: #f8fbf4;
  --muted: #a9b9b2;
  --line-dark: rgba(240, 250, 244, 0.18);
  --line-light: rgba(7, 21, 20, 0.22);
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --display: "Iowan Old Style", "Baskerville", "Times New Roman", serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --gutter: clamp(1rem, 3vw, 3rem);
  --measure: 74rem;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--ink); }
body {
  margin: 0;
  min-width: 20rem;
  overflow-x: clip;
  background: var(--ink);
  color: var(--white);
  font-family: var(--sans);
  line-height: 1.55;
  text-rendering: optimizeLegibility;
}
img, video { display: block; max-width: 100%; }
a { color: inherit; text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 0.16em; }
:focus-visible { outline: 3px solid var(--cyan); outline-offset: 4px; }

.skip-link {
  position: fixed;
  z-index: 100;
  left: 1rem;
  top: 1rem;
  padding: 0.75rem 1rem;
  min-height: 2.75rem;
  background: var(--lime);
  color: var(--ink);
  font-weight: 800;
  transform: translateY(-180%);
}
.skip-link:focus { transform: translateY(0); }

.site-nav {
  position: relative;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 4.5rem;
  padding: 0 var(--gutter);
  border-bottom: 1px solid var(--line-dark);
  background: rgba(7, 21, 20, 0.96);
}
.site-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  text-decoration: none;
}
.brand { font-family: var(--display); font-size: 1.08rem; font-weight: 700; }
.nav-links { display: flex; align-items: center; gap: clamp(0.85rem, 2vw, 1.8rem); font-size: 0.86rem; font-weight: 750; }
.nav-links a:last-child { min-width: 2.75rem; justify-content: center; border: 1px solid var(--line-dark); }

.hero {
  position: relative;
  isolation: isolate;
  display: grid;
  align-content: center;
  min-height: calc(100svh - 4.5rem);
  padding: clamp(3rem, 9vh, 7rem) var(--gutter) clamp(3rem, 8vh, 6rem);
  overflow: hidden;
  background:
    linear-gradient(90deg, transparent 0 66%, rgba(200, 255, 81, 0.08) 66% 66.2%, transparent 66.2%),
    radial-gradient(circle at 84% 45%, rgba(115, 232, 243, 0.16) 0 1px, transparent 1.5px 11rem),
    var(--ink);
}
.hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  right: clamp(-8rem, -4vw, -2rem);
  top: 12%;
  width: clamp(16rem, 32vw, 31rem);
  aspect-ratio: 1;
  border: 1px solid rgba(115, 232, 243, 0.3);
  border-radius: 50% 50% 44% 56%;
  box-shadow: inset 0 -4rem 8rem rgba(115, 232, 243, 0.08);
}
.eyebrow, .step, .outcome-kicker, .mechanism-label {
  margin: 0 0 1.25rem;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.73rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.eyebrow span { color: var(--lime); }
h1, h2, h3, p { overflow-wrap: anywhere; }
h1 {
  max-width: 13ch;
  margin: 0;
  font-family: var(--display);
  font-size: clamp(3.15rem, 8.5vw, 8.4rem);
  font-weight: 500;
  line-height: 0.88;
  letter-spacing: -0.055em;
}
.deck {
  max-width: 48rem;
  margin: clamp(1.75rem, 4vw, 3rem) 0 0;
  color: #dbe7e0;
  font-size: clamp(1.08rem, 2vw, 1.45rem);
  line-height: 1.45;
}
.hero-proof {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  max-width: 58rem;
  margin-top: clamp(1.5rem, 4vw, 2.75rem);
  border-top: 1px solid var(--line-dark);
  border-bottom: 1px solid var(--line-dark);
}
.hero-proof p { margin: 0; padding: 0.85rem 1rem 0.85rem 0; color: var(--muted); font-size: 0.88rem; }
.hero-proof p + p { padding-left: 1rem; border-left: 1px solid var(--line-dark); }
.hero-proof strong { display: block; color: var(--white); font-size: 0.98rem; }
.hero-source {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  width: fit-content;
  min-height: 2.75rem;
  margin-top: 1rem;
  color: var(--cyan);
  font-size: 0.86rem;
  font-weight: 700;
}

.section { padding: clamp(4.5rem, 9vw, 9rem) var(--gutter); }
.section > * { width: min(100%, var(--measure)); margin-inline: auto; }
.section-dark { background: var(--ink); color: var(--white); }
.section-light { color-scheme: light; background: var(--paper); color: var(--ink); }
.section-copper { color-scheme: dark; background: var(--copper-dark); color: var(--white); }
.section-sources { color-scheme: dark; background: #0e201e; color: var(--white); }
.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(16rem, 1fr);
  gap: clamp(1.5rem, 6vw, 7rem);
  align-items: end;
  margin-bottom: clamp(2.5rem, 6vw, 5rem);
}
.section-heading .step { grid-column: 1 / -1; margin-bottom: -0.25rem; color: currentColor; opacity: 0.62; }
.section-heading h2 {
  max-width: 15ch;
  margin: 0;
  font-family: var(--display);
  font-size: clamp(2.7rem, 6vw, 6.4rem);
  font-weight: 500;
  line-height: 0.94;
  letter-spacing: -0.045em;
}
.section-heading > p:last-child { max-width: 37rem; margin: 0; font-size: clamp(1rem, 1.4vw, 1.16rem); }

.comparison { border-top: 1px solid var(--line-dark); }
.timeline-control {
  display: grid;
  grid-template-columns: auto minmax(8rem, 1fr) 4rem;
  gap: 1rem;
  align-items: center;
  padding: 1rem 0;
}
.timeline-control label { font-size: 0.85rem; font-weight: 750; }
.timeline-control input { width: 100%; min-height: 2.75rem; accent-color: var(--lime); cursor: ew-resize; }
.timeline-control output { color: var(--lime); font-family: var(--mono); font-size: 0.82rem; text-align: right; }
.video-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; background: var(--line-dark); }
.video-panel { position: relative; margin: 0; padding: 1rem; background: #020605; }
.video-panel video { width: 100%; aspect-ratio: 16 / 10; background: #000; object-fit: contain; }
.video-label {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  min-height: 2.75rem;
  align-items: center;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 750;
}
.video-label span { color: var(--white); font-family: var(--mono); letter-spacing: 0.08em; }
.charged .video-label span { color: var(--lime); }
.video-panel figcaption { min-height: 3.2rem; margin-top: 0.85rem; color: var(--muted); font-size: 0.84rem; }
.media-note { margin: 0; padding: 1rem 0; color: var(--muted); font-size: 0.76rem; }
.control-note {
  display: grid;
  grid-template-columns: minmax(12rem, 0.8fr) minmax(18rem, 1.5fr);
  gap: 2rem;
  margin-top: 2.5rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--lime);
  border-bottom: 1px solid var(--line-dark);
}
.control-note strong { color: var(--lime); font-family: var(--display); font-size: 1.7rem; line-height: 1.1; }
.control-note p { margin: 0; color: #c8d5ce; }

.charge-path {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--ink);
}
.charge-path li { position: relative; min-height: 16rem; padding: 1.5rem 1.5rem 1.5rem 0; border-bottom: 1px solid var(--line-light); }
.charge-path li + li { padding-left: 1.5rem; border-left: 1px solid var(--line-light); }
.charge-path li:not(:last-child)::after { content: "→"; position: absolute; right: -0.85rem; top: 50%; z-index: 2; width: 1.7rem; color: var(--copper-dark); background: var(--paper); font-size: 1.8rem; text-align: center; }
.charge-index { display: block; color: var(--copper-dark); font-family: var(--mono); font-size: 0.75rem; }
.charge-path strong { display: block; margin-top: 2.5rem; font-family: var(--display); font-size: clamp(2.25rem, 5vw, 5.25rem); font-weight: 500; line-height: 0.95; letter-spacing: -0.04em; }
.charge-path small { display: block; max-width: 15rem; margin-top: 1rem; font-size: 0.83rem; }
.calculation {
  display: grid;
  grid-template-columns: minmax(12rem, 0.8fr) minmax(18rem, 1.4fr);
  gap: clamp(2rem, 6vw, 7rem);
  align-items: center;
  margin-top: 3rem;
  padding: 2rem 0;
  border-top: 1px solid var(--line-light);
}
.calculation-number { margin: 0; color: var(--copper-dark); font-family: var(--display); font-size: clamp(5rem, 12vw, 11rem); line-height: 0.8; letter-spacing: -0.07em; }
.calculation h3 { margin: 0; font-family: var(--display); font-size: clamp(1.7rem, 3vw, 2.8rem); font-weight: 500; line-height: 1.05; }
.calculation div p { max-width: 38rem; margin: 1rem 0 0; }

.outcome-compare { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; background: rgba(255,255,255,0.25); }
.outcome-compare article { min-height: 22rem; padding: clamp(1.5rem, 4vw, 3.5rem); background: var(--copper-dark); }
.outcome-compare article:last-child { background: var(--ink); }
.outcome-kicker { color: rgba(255,255,255,0.75); }
.outcome-compare h3 { max-width: 8ch; margin: 5rem 0 1rem; font-family: var(--display); font-size: clamp(2.7rem, 6vw, 5.6rem); font-weight: 500; line-height: 0.9; }
.outcome-compare p:last-child { max-width: 31rem; color: #e3d5ce; }
.precision-note { margin-top: 2rem; padding: 1.25rem 0; border-top: 1px solid rgba(255,255,255,0.35); border-bottom: 1px solid rgba(255,255,255,0.35); }

.mechanism-chain {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-dark);
}
.mechanism-chain li { position: relative; min-height: 18rem; padding: 1.5rem; border-bottom: 1px solid var(--line-dark); }
.mechanism-chain li + li { border-left: 1px solid var(--line-dark); }
.mechanism-chain li::after { content: ""; position: absolute; left: calc(100% - 1px); top: 4.5rem; z-index: 2; width: 2px; height: 5rem; background: var(--lime); }
.mechanism-chain li:last-child::after { display: none; }
.mechanism-chain span { color: var(--lime); font-family: var(--mono); font-size: 0.75rem; }
.mechanism-chain h3 { margin: 4rem 0 0.6rem; font-family: var(--display); font-size: clamp(1.8rem, 3.5vw, 3.4rem); font-weight: 500; line-height: 1; }
.mechanism-chain p { margin: 0; color: var(--muted); font-size: 0.88rem; }
.mechanism-label { margin-top: 1rem; text-align: right; }

.conditions-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 0;
  border-top: 2px solid var(--ink);
}
.conditions-grid div { min-height: 9rem; padding: 1.25rem 1.25rem 1.25rem 0; border-bottom: 1px solid var(--line-light); }
.conditions-grid div:not(:nth-child(3n + 1)) { padding-left: 1.25rem; border-left: 1px solid var(--line-light); }
.conditions-grid dt { color: var(--copper-dark); font-family: var(--mono); font-size: 0.72rem; font-weight: 750; letter-spacing: 0.08em; text-transform: uppercase; }
.conditions-grid dd { margin: 1.75rem 0 0; font-family: var(--display); font-size: clamp(1.8rem, 3vw, 3rem); line-height: 1; }
.boundary-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; margin-top: 3rem; background: var(--line-light); }
.boundary-grid article { padding: clamp(1.5rem, 4vw, 3rem); background: var(--paper-soft); }
.boundary-grid article:last-child { background: var(--ink); color: var(--white); }
.boundary-grid h3 { margin: 0; font-family: var(--display); font-size: 2rem; font-weight: 500; }
.boundary-grid p { margin-bottom: 0; }

.source-list { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line-dark); }
.source-list a {
  display: grid;
  grid-template-columns: minmax(12rem, 0.75fr) minmax(16rem, 1.25fr);
  gap: 2rem;
  align-items: center;
  min-height: 5rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--line-dark);
  text-decoration: none;
}
.source-list a:hover strong { color: var(--lime); }
.source-list strong { font-family: var(--display); font-size: 1.35rem; font-weight: 500; }
.source-list span { color: var(--muted); font-size: 0.85rem; }
.credit { max-width: 52rem; margin: 2.5rem 0 0; color: var(--muted); font-size: 0.78rem; }

.site-footer { padding: 2rem var(--gutter); border-top: 1px solid var(--line-dark); background: var(--ink); color: var(--muted); font-size: 0.82rem; }
.site-footer p { width: min(100%, var(--measure)); margin: 0 auto; }
.site-footer a { display: inline-flex; align-items: center; min-height: 2.75rem; }
.site-footer span { float: right; }

.error-page { display: grid; place-items: center; min-height: 100svh; padding: var(--gutter); background: var(--ink); color: var(--white); }
.error-page main { max-width: 42rem; }
.error-page h1 { font-size: clamp(4rem, 14vw, 10rem); }
.error-page p { font-size: 1.1rem; }
.error-page a { display: inline-flex; align-items: center; min-height: 2.75rem; color: var(--lime); font-weight: 750; }

@media (max-width: 52rem) {
  .hero { min-height: auto; padding-top: 4rem; padding-bottom: 4rem; }
  .hero::after { opacity: 0.5; }
  .hero-proof { grid-template-columns: 1fr; }
  .hero-proof p + p { padding-left: 0; border-left: 0; border-top: 1px solid var(--line-dark); }
  .section-heading { grid-template-columns: 1fr; gap: 1.25rem; }
  .section-heading .step { grid-column: 1; }
  .section-heading h2 { max-width: 18ch; }
  .video-grid, .outcome-compare, .boundary-grid { grid-template-columns: 1fr; }
  .control-note, .calculation { grid-template-columns: 1fr; gap: 1rem; }
  .charge-path { grid-template-columns: 1fr; }
  .charge-path li { min-height: 10rem; padding: 1.25rem 0; }
  .charge-path li + li { padding-left: 0; border-left: 0; }
  .charge-path li:not(:last-child)::after { content: "↓"; right: 0; top: auto; bottom: -1rem; background: var(--paper); }
  .charge-path strong { margin-top: 1rem; }
  .mechanism-chain { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .mechanism-chain li:nth-child(3) { border-left: 0; }
  .mechanism-chain li::after { display: none; }
  .conditions-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .conditions-grid div:not(:nth-child(3n + 1)) { padding-left: 0; border-left: 0; }
  .conditions-grid div:nth-child(even) { padding-left: 1rem; border-left: 1px solid var(--line-light); }
}

@media (max-width: 34rem) {
  .site-nav { min-height: 4rem; }
  .nav-links a:not(:last-child) { display: none; }
  .hero { min-height: calc(100svh - 4rem); padding-top: 2.2rem; padding-bottom: 2.2rem; }
  h1 { font-size: clamp(3rem, 15.2vw, 4.6rem); line-height: 0.9; }
  .deck { margin-top: 1.35rem; font-size: 1rem; }
  .hero-proof { margin-top: 1.25rem; }
  .hero-proof p { display: grid; grid-template-columns: 5.5rem 1fr; gap: 0.5rem; padding: 0.55rem 0; font-size: 0.75rem; }
  .hero-proof strong { font-size: 0.82rem; }
  .hero-source { margin-top: 0.7rem; font-size: 0.75rem; }
  .section { padding-top: 4rem; padding-bottom: 4rem; }
  .timeline-control { grid-template-columns: 1fr 3.5rem; }
  .timeline-control label { grid-column: 1 / -1; }
  .mechanism-chain { grid-template-columns: 1fr; }
  .mechanism-chain li + li { border-left: 0; }
  .mechanism-chain li { min-height: 12rem; }
  .mechanism-chain h3 { margin-top: 2rem; }
  .conditions-grid { grid-template-columns: 1fr; }
  .conditions-grid div, .conditions-grid div:nth-child(even) { min-height: 7rem; padding-left: 0; border-left: 0; }
  .conditions-grid dd { margin-top: 0.9rem; }
  .source-list a { grid-template-columns: 1fr; gap: 0.25rem; }
  .site-footer span { display: block; float: none; margin-top: 0.4rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

@media (prefers-contrast: more) {
  :root { --muted: #d5e1da; --line-dark: rgba(255,255,255,0.55); --line-light: rgba(0,0,0,0.55); }
}