:root {
  --bg: #050505;
  --surface: #0a0a0d;
  --surface-2: #0e1017;
  --text: #e2e8f0;
  --muted: #8b96a8;
  --dim: #718096;
  --line: rgba(255, 255, 255, 0.09);
  --violet: #a78bfa;
  --violet-strong: #8b5cf6;
  --cyan: #22d3ee;
  --green: #34d399;
  --amber: #fbbf24;
  --red: #fb7185;
  --font-sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
.skip-link {
  position: fixed;
  top: .65rem;
  left: .65rem;
  z-index: 200;
  transform: translateY(-160%);
  padding: .65rem .85rem;
  border: 1px solid var(--cyan);
  background: #050505;
  color: #cffafe;
  font-family: var(--font-mono);
  font-size: .75rem;
  text-decoration: none;
  transition: transform .2s ease;
}
.skip-link:focus { transform: translateY(0); }
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem 2.5rem;
  background: rgba(5, 5, 5, 0.9);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
}
.nav-left { display: flex; align-items: center; gap: 1rem; }
.nav-brand {
  display: flex;
  align-items: center;
  gap: .5rem;
  color: var(--text);
  font-size: .9rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-decoration: none;
}
.nav-brand img { display: block; width: 20px; height: 20px; }
.nav-breadcrumb {
  display: flex;
  align-items: center;
  gap: .5rem;
  color: var(--dim);
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .08em;
}
.nav-breadcrumb::before { content: "/"; color: rgba(255,255,255,.18); }
.nav-breadcrumb a { color: var(--cyan); text-decoration: none; transition: color .2s; }
.nav-breadcrumb a:hover { color: var(--text); }
.nav-links { display: flex; align-items: center; gap: 2rem; margin: 0; padding: 0; list-style: none; }
.nav-links a {
  color: var(--muted);
  font-size: .85rem;
  letter-spacing: .02em;
  text-decoration: none;
  transition: color .2s;
}
.nav-links a:hover { color: var(--text); }
.nav-cta {
  padding: .5rem 1.2rem;
  border: 1px solid rgba(139,92,246,.5);
  background: rgba(139,92,246,.08);
  color: var(--violet);
  font-size: .78rem;
  font-weight: 500;
  letter-spacing: .04em;
  text-decoration: none;
  transition: all .2s;
}
.nav-cta:hover { border-color: var(--violet-strong); background: rgba(139,92,246,.2); color: white; }

.hero {
  position: relative;
  overflow: hidden;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 8rem 2.5rem 3.5rem;
  border-bottom: 1px solid var(--line);
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 24% 28%, rgba(139, 92, 246, .18), transparent 32%),
    radial-gradient(circle at 78% 68%, rgba(34, 211, 238, .10), transparent 30%),
    linear-gradient(rgba(255,255,255,.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.025) 1px, transparent 1px);
  background-size: auto, auto, 48px 48px, 48px 48px;
  mask-image: linear-gradient(to bottom, black 65%, transparent);
}
.hero-inner { position: relative; width: min(960px, 100%); text-align: center; }
.eyebrow, .section-label, .figure-label {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--violet);
}
.eyebrow { display: flex; align-items: center; justify-content: center; gap: .8rem; color: var(--cyan); }
.eyebrow::before { content: ""; display: block; width: 32px; height: 1px; background: var(--cyan); }
.hero h1 {
  max-width: 900px;
  margin: 1.5rem auto 2rem;
  color: #fff;
  font-size: clamp(2.4rem, 5vw, 4.2rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -.03em;
}
.hero h1 em { color: var(--cyan); font-style: normal; }
.hero-sub {
  max-width: 700px;
  margin: 0 auto;
  color: #aab4c3;
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  line-height: 1.55;
}
.byline {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: .65rem;
  margin-top: 2rem;
  color: var(--dim);
  font-family: var(--font-mono);
  font-size: .69rem;
  letter-spacing: .05em;
  text-transform: uppercase;
}
.byline strong { color: #cbd5e1; font-weight: 500; }
.series-nav {
  display: inline-flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: .65rem;
  margin-top: 2.25rem;
  padding: .75rem 1rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(0,0,0,.35);
  font-family: var(--font-mono);
  font-size: .68rem;
  color: var(--muted);
}
.series-nav a { color: var(--cyan); text-decoration: none; }

main { overflow: hidden; }
article { padding: 0 1.25rem; }
.prose, .prose-wide { width: min(720px, 100%); margin-inline: auto; }
.prose-wide { width: min(1040px, 100%); }
.opening {
  padding: 5.5rem 0 2rem;
  font-size: clamp(1.18rem, 2vw, 1.45rem);
  line-height: 1.75;
  color: #cbd5e1;
}
.opening p:first-child::first-letter {
  float: left;
  margin: .1rem .65rem 0 0;
  color: var(--cyan);
  font-size: 4.2rem;
  font-weight: 760;
  line-height: .8;
}
section { padding: 5rem 0; }
.section-rule { width: min(1040px, 100%); margin: 0 auto; border: 0; border-top: 1px solid var(--line); }
h2 {
  margin: .7rem 0 1.2rem;
  color: #f8fafc;
  font-size: clamp(2rem, 4.5vw, 3.45rem);
  line-height: 1.08;
  letter-spacing: -.04em;
}
h3 { margin: .4rem 0 .75rem; color: #f1f5f9; font-size: 1.12rem; line-height: 1.35; }
p { margin: 0 0 1.25rem; }
.section-intro { color: #aab4c3; font-size: 1.12rem; line-height: 1.75; }
.callout {
  margin: 2.4rem auto;
  padding: 1.6rem 1.7rem;
  border: 1px solid rgba(34, 211, 238, .2);
  border-left: 3px solid var(--cyan);
  background: rgba(34, 211, 238, .035);
  color: #cbd5e1;
}
.callout strong { color: white; }
.one-line {
  margin: 2.5rem auto;
  padding: 1.7rem;
  border: 1px solid rgba(167,139,250,.24);
  background: linear-gradient(120deg, rgba(139,92,246,.08), rgba(34,211,238,.035));
  color: #f1f5f9;
  font-size: 1.2rem;
  font-weight: 650;
  line-height: 1.6;
  text-align: center;
}
.plain-english {
  margin: 2rem 0;
  padding: 1.35rem 1.5rem;
  border-left: 3px solid var(--violet);
  background: rgba(139,92,246,.045);
  color: #cbd5e1;
}
.plain-english::before {
  content: "IN PLAIN ENGLISH";
  display: block;
  margin-bottom: .55rem;
  color: var(--violet);
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .13em;
}
.flow-block {
  margin: 2rem 0;
  padding: 1.5rem;
  overflow-x: auto;
  border: 1px solid var(--line);
  background: #08090d;
  color: #cbd5e1;
  font-family: var(--font-mono);
  font-size: .8rem;
  line-height: 1.75;
  white-space: pre;
}
.example-box {
  margin: 2rem 0;
  padding: 1.5rem;
  border: 1px solid var(--line);
  background: rgba(10,10,14,.82);
}
.example-box .example-title {
  margin-bottom: .85rem;
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: .65rem;
  letter-spacing: .11em;
  text-transform: uppercase;
}
.example-box p:last-child, .plain-english p:last-child { margin-bottom: 0; }
.takeaway {
  margin-top: 2.2rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
  color: #dbeafe;
  font-weight: 600;
}
.takeaway::before {
  content: "TAKEAWAY → ";
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .06em;
}
.term {
  color: #f8fafc;
  font-weight: 700;
}
.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.65rem;
  height: 1.65rem;
  margin-right: .55rem;
  border: 1px solid rgba(34,211,238,.35);
  border-radius: 50%;
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: .68rem;
}
.compare-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-top: 2rem;
}
.compare-panel {
  padding: 1.5rem;
  border: 1px solid var(--line);
  background: rgba(10,10,14,.82);
}
.compare-panel h3 { color: var(--cyan); }
.compare-panel ul { margin: .75rem 0 0; padding-left: 1.2rem; color: var(--muted); }
.compare-panel li { margin: .45rem 0; }
.source-note { color: var(--dim); font-size: .76rem; }

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin: 3rem auto 0;
  border: 1px solid var(--line);
  background: var(--line);
}
.stat { padding: 1.6rem; background: rgba(7, 8, 12, .96); }
.stat-number { color: var(--cyan); font-size: clamp(1.65rem, 3vw, 2.5rem); font-weight: 750; letter-spacing: -.04em; }
.stat-label { color: var(--muted); font-size: .78rem; line-height: 1.45; }

.illustration {
  margin: 3rem auto;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: linear-gradient(135deg, rgba(139,92,246,.035), rgba(34,211,238,.025));
  overflow: hidden;
}
.illustration-inner:focus-visible, .decision-table:focus-visible, .flow-block:focus-visible, .formula:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}
.illustration-inner { padding: clamp(1rem, 3vw, 2rem); overflow-x: auto; }
.illustration svg { display: block; width: 100%; min-width: 680px; height: auto; }
figcaption {
  padding: .85rem 1rem;
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-family: var(--font-mono);
  font-size: .65rem;
  line-height: 1.6;
}

.method-grid, .risk-grid, .metric-grid, .steps-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-top: 2.5rem;
}
.method-card, .risk-card, .metric-card, .step-card {
  position: relative;
  padding: 1.55rem;
  border: 1px solid var(--line);
  background: rgba(10, 10, 14, .82);
}
.method-card::before {
  content: attr(data-num);
  position: absolute;
  top: 1rem;
  right: 1rem;
  color: rgba(167, 139, 250, .3);
  font-family: var(--font-mono);
  font-size: .68rem;
}
.card-tag {
  display: inline-block;
  margin-bottom: .8rem;
  padding: .25rem .5rem;
  border: 1px solid rgba(167,139,250,.22);
  color: var(--violet);
  font-family: var(--font-mono);
  font-size: .62rem;
  letter-spacing: .1em;
  text-transform: uppercase;
}
.method-card p, .risk-card p, .metric-card p, .step-card p { margin: 0; color: var(--muted); font-size: .9rem; }
.best-for { margin-top: 1rem; color: var(--cyan); font-family: var(--font-mono); font-size: .65rem; letter-spacing: .06em; }

.decision-table { margin-top: 2.5rem; overflow-x: auto; border: 1px solid var(--line); }
table { width: 100%; min-width: 760px; border-collapse: collapse; background: rgba(8,8,12,.85); }
th, td { padding: 1rem; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { color: var(--violet); font-family: var(--font-mono); font-size: .64rem; letter-spacing: .1em; text-transform: uppercase; }
td { color: #aab4c3; font-size: .82rem; line-height: 1.5; }
td:first-child { color: #e2e8f0; font-weight: 650; }
tr:last-child td { border-bottom: 0; }
.dot { display: inline-block; width: 7px; height: 7px; margin-right: .45rem; border-radius: 50%; background: var(--cyan); }

.formula {
  margin: 2rem 0;
  padding: 1.4rem;
  overflow-x: auto;
  border: 1px solid var(--line);
  background: #08090d;
  color: #d8b4fe;
  font-family: var(--font-mono);
  font-size: .88rem;
  text-align: center;
}
.checklist { list-style: none; margin: 1.5rem 0 0; padding: 0; }
.checklist li { position: relative; padding: .85rem 0 .85rem 2rem; border-bottom: 1px solid var(--line); color: #aab4c3; }
.checklist li::before { content: "✓"; position: absolute; left: .25rem; color: var(--green); font-family: var(--font-mono); }

.references { padding: 4rem 0 5rem; }
.reference-list { list-style: none; padding: 0; counter-reset: refs; }
.reference-list li { counter-increment: refs; position: relative; padding: 1rem 0 1rem 2.5rem; border-bottom: 1px solid var(--line); color: var(--muted); font-size: .82rem; }
.reference-list li::before { content: "[" counter(refs) "]"; position: absolute; left: 0; color: var(--violet); font-family: var(--font-mono); }
.reference-list a { color: #cbd5e1; text-decoration-color: rgba(34,211,238,.35); text-underline-offset: 3px; }

.next-band {
  padding: 5rem 1.25rem;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(120deg, rgba(139,92,246,.08), rgba(34,211,238,.04));
  text-align: center;
}
.next-band h2 { max-width: 760px; margin-inline: auto; }
.next-band p { max-width: 660px; margin: 0 auto 1.6rem; color: var(--muted); }
.button {
  display: inline-block;
  padding: .8rem 1.1rem;
  border: 1px solid rgba(34,211,238,.45);
  background: rgba(34,211,238,.08);
  color: #cffafe;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .06em;
  text-decoration: none;
  text-transform: uppercase;
}
.button:hover { background: rgba(34,211,238,.15); }
footer { display: flex; justify-content: space-between; gap: 1rem; padding: 2rem clamp(1.25rem, 4vw, 4rem); color: var(--dim); font-size: .7rem; }
footer p { margin: 0; }
footer a { color: var(--muted); }

.fade-up { opacity: 1; transform: none; }
.js .fade-up { opacity: 0; transform: translateY(18px); transition: opacity .7s ease, transform .7s ease; }
.js .fade-up.visible { opacity: 1; transform: none; }

@media (max-width: 720px) {
  .site-nav { padding: 1rem 1.2rem; }
  .nav-links { display: none; }
  .hero { min-height: 100vh; padding: 7rem 1.5rem 4rem; }
  .hero h1 { font-size: 2.8rem; }
  .stats, .method-grid, .risk-grid, .metric-grid, .steps-grid, .compare-grid { grid-template-columns: 1fr; }
  section { padding: 4rem 0; }
  footer { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .fade-up { opacity: 1; transform: none; transition: none; }
}