:root {
  --bg: #ffffff;
  --bg-subtle: #f5f5f7;
  --text: #1d1d1f;
  --text-secondary: #6e6e73;
  --border: #d2d2d7;
  --red: #ff3b30;
  --teal: #06b6a8;
  --mono: 'SF Mono', 'IBM Plex Mono', ui-monospace, Menlo, monospace;
  --sans: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Helvetica Neue', Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  padding: 16px 24px;
  background: rgba(255,255,255,0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav a {
  color: var(--text);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.01em;
  opacity: 0.7;
  transition: opacity 0.2s ease;
}
.nav a:hover, .nav a.active { opacity: 1; }

.nav .brand {
  font-weight: 600;
  font-size: 14px;
  opacity: 1;
  margin-right: auto;
}

section {
  max-width: 980px;
  margin: 0 auto;
  padding: 120px 24px;
}

section.tight { padding-top: 60px; padding-bottom: 60px; }

.eyebrow {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

h1 {
  font-size: clamp(40px, 6vw, 64px);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.05;
  margin: 0 0 20px 0;
}

h2 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.015em;
  line-height: 1.1;
  margin: 0 0 16px 0;
}

.lede {
  font-size: 21px;
  line-height: 1.55;
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 0 8px 0;
}

.hero {
  text-align: center;
  padding-top: 160px;
  padding-bottom: 100px;
}
.hero .lede { margin: 0 auto; }

.hero-stat {
  margin-top: 64px;
}
.hero-stat .value {
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(72px, 12vw, 128px);
  line-height: 1;
  letter-spacing: -0.02em;
}
.hero-stat .label {
  font-size: 15px;
  color: var(--text-secondary);
  margin-top: 12px;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 18px;
  overflow: hidden;
  margin-top: 48px;
}
.stat-cell {
  background: var(--bg);
  padding: 28px 24px;
  text-align: center;
}
.stat-cell .value {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 32px;
  letter-spacing: -0.01em;
}
.stat-cell .label {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 8px;
  letter-spacing: 0.02em;
}

.caveat {
  margin-top: 32px;
  padding: 14px 20px;
  background: var(--bg-subtle);
  border-radius: 12px;
  font-size: 14px;
  color: var(--text-secondary);
  font-family: var(--mono);
  max-width: 640px;
}

.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0;
}

.panel {
  background: var(--bg-subtle);
  border-radius: 18px;
  padding: 32px;
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
}

.walkthrough-box {
  background: var(--bg-subtle);
  border-radius: 16px;
  padding: 24px 28px;
  margin-bottom: 12px;
}
.walkthrough-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 12px;
}
.walkthrough-node {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 8px;
}
.walkthrough-text {
  font-size: 17px;
  line-height: 1.55;
  color: var(--text);
  min-height: 78px;
}
.walkthrough-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 18px;
}
.wt-btn {
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease, opacity 0.15s ease;
}
.wt-btn:hover:not(:disabled) {
  border-color: var(--text-secondary);
  background: var(--bg-subtle);
}
.wt-btn:disabled {
  opacity: 0.35;
  cursor: default;
}
.walkthrough-dots {
  display: flex;
  gap: 8px;
}
.walkthrough-dots .wt-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--border);
  cursor: pointer;
  border: none;
  padding: 0;
}
.walkthrough-dots .wt-dot.active {
  background: var(--text);
}

.tour-aside {
  font-size: 14px;
  color: var(--text-secondary);
  margin: 0 0 24px 0;
}
.tour-link {
  font-family: var(--mono);
  font-size: 14px;
  color: var(--text);
  background: none;
  border: none;
  border-bottom: 1px solid var(--text-secondary);
  padding: 0;
  cursor: pointer;
}
.tour-link:hover {
  border-bottom-color: var(--text);
}

.lookup-controls {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

select {
  font-family: var(--mono);
  font-size: 15px;
  padding: 10px 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  min-width: 140px;
}

.lookup-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 32px;
  align-items: start;
}
@media (max-width: 800px) {
  .lookup-grid { grid-template-columns: 1fr; }
}

.graph-card {
  background: var(--bg-subtle);
  border-radius: 20px;
  padding: 8px;
}

#graph-canvas {
  display: block;
  width: 100%;
  height: auto;
  cursor: grab;
  touch-action: none;
}

.legend {
  display: flex;
  gap: 20px;
  font-size: 13px;
  color: var(--text-secondary);
  padding: 12px 16px 0 16px;
}
.legend .dot {
  display: inline-block;
  width: 8px; height: 8px;
  border-radius: 50%;
  margin-right: 6px;
}

.info-card {
  background: var(--bg-subtle);
  border-radius: 18px;
  padding: 24px;
}
.info-row { margin-bottom: 20px; }
.info-row:last-child { margin-bottom: 0; }
.info-row .field-label {
  font-size: 12px;
  color: var(--text-secondary);
  letter-spacing: 0.03em;
  margin-bottom: 6px;
}
.chip {
  display: inline-block;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 14px;
  padding: 5px 12px;
  border-radius: 8px;
}
.chip-mule { color: var(--red); background: rgba(255,59,48,0.1); }
.chip-normal { color: var(--teal); background: rgba(6,182,168,0.1); }

.confidence-value {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 24px;
}

.outcome {
  margin-top: 8px;
  padding: 14px 16px;
  border-radius: 12px;
  font-family: var(--mono);
  font-size: 13px;
  border-left: 3px solid var(--teal);
  background: var(--bg);
}
.outcome.flagged { border-left-color: var(--red); }

.pattern-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 32px 0;
}
@media (max-width: 640px) { .pattern-grid { grid-template-columns: 1fr; } }

.pattern-card {
  background: var(--bg-subtle);
  border-radius: 18px;
  padding: 28px;
}
.pattern-card .value {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 44px;
  letter-spacing: -0.01em;
}
.pattern-card .label {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 8px;
}
.pattern-card .sub {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 4px;
}

.fp-list { margin-top: 12px; }
.fp-row {
  display: flex;
  gap: 16px;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}
.fp-row:last-child { border-bottom: none; }
.fp-node {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 14px;
  min-width: 80px;
}
.fp-verdict {
  font-size: 15px;
  color: var(--text-secondary);
}

footer {
  text-align: center;
  padding: 60px 24px 80px 24px;
  font-size: 13px;
  color: var(--text-secondary);
}
footer a { color: var(--text-secondary); }