:root {
  --bg: #0A1628;
  --surface: #0F1F36;
  --surface-2: #162840;
  --fg: #F0EFE9;
  --fg-muted: #8A9BB0;
  --accent: #E8A838;
  --accent-dim: rgba(232, 168, 56, 0.12);
  --border: rgba(240, 239, 233, 0.08);
  --serif: 'Instrument Serif', Georgia, serif;
  --sans: 'DM Sans', system-ui, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 22, 40, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 clamp(24px, 5vw, 80px);
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.wordmark {
  font-family: var(--serif);
  font-size: 22px;
  letter-spacing: -0.02em;
  color: var(--fg);
}
.header-tag {
  font-size: 12px;
  color: var(--fg-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 500;
}

/* Section label */
.section-label {
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 48px;
}

/* Hero */
.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: clamp(64px, 10vw, 120px) clamp(24px, 5vw, 80px);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.hero-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 28px;
}
.label-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}
.hero-headline {
  font-family: var(--serif);
  font-size: clamp(42px, 6vw, 72px);
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--fg);
  margin-bottom: 28px;
}
.hero-sub {
  font-size: 18px;
  line-height: 1.65;
  color: var(--fg-muted);
  max-width: 460px;
  margin-bottom: 40px;
}
.hero-meta {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}
.meta-pill {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.meta-value {
  font-size: 22px;
  font-weight: 600;
  color: var(--accent);
  font-feature-settings: 'tnum';
}
.meta-label {
  font-size: 12px;
  color: var(--fg-muted);
}

/* Signal grid */
.hero-visual {
  padding: 40px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
}
.signal-grid {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.signal-row {
  display: grid;
  grid-template-columns: 90px 1fr auto;
  align-items: center;
  gap: 16px;
}
.signal-label {
  font-size: 12px;
  color: var(--fg-muted);
  letter-spacing: 0.04em;
  font-weight: 500;
}
.signal-bar {
  height: 3px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--accent) 0%, rgba(232,168,56,0.3) 100%);
}
.s-90 { width: 90%; }
.s-75 { width: 75%; }
.s-85 { width: 85%; }
.s-95 { width: 95%; }
.signal-val {
  font-size: 12px;
  color: var(--fg-muted);
  white-space: nowrap;
}

/* How it works */
.how {
  background: var(--surface);
  padding: clamp(64px, 8vw, 100px) clamp(24px, 5vw, 80px);
}
.loop-diagram {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr;
  align-items: start;
  gap: 0;
}
.loop-step {
  padding: 32px 28px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
}
.loop-arrow {
  display: flex;
  align-items: center;
  font-size: 22px;
  color: var(--accent);
  padding: 0 4px;
  padding-top: 48px;
}
.step-num {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 12px;
}
.loop-step h3 {
  font-family: var(--serif);
  font-size: 20px;
  margin-bottom: 10px;
  color: var(--fg);
}
.loop-step p {
  font-size: 14px;
  color: var(--fg-muted);
  line-height: 1.6;
}

/* Math */
.math {
  max-width: 1200px;
  margin: 0 auto;
  padding: clamp(64px, 8vw, 100px) clamp(24px, 5vw, 80px);
}
.math-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}
.math-card {
  padding: 36px 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
}
.math-card.highlight {
  border-color: rgba(232, 168, 56, 0.3);
  background: rgba(232, 168, 56, 0.04);
}
.math-icon {
  margin-bottom: 20px;
}
.math-value {
  font-family: var(--serif);
  font-size: 40px;
  color: var(--accent);
  margin-bottom: 6px;
}
.math-label {
  font-size: 15px;
  font-weight: 500;
  color: var(--fg);
  margin-bottom: 8px;
}
.math-detail {
  font-size: 13px;
  color: var(--fg-muted);
  line-height: 1.5;
}
.math-conclusion {
  font-size: 18px;
  color: var(--fg-muted);
  max-width: 600px;
  line-height: 1.7;
  padding: 28px 32px;
  background: var(--accent-dim);
  border: 1px solid rgba(232, 168, 56, 0.15);
  border-radius: 8px;
}
.math-conclusion strong {
  color: var(--accent);
}

/* Principles */
.principles {
  background: var(--surface);
  padding: clamp(64px, 8vw, 100px) clamp(24px, 5vw, 80px);
}
.principles-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 48px;
}
.principle {
  display: grid;
  grid-template-columns: 32px 1fr;
  gap: 24px;
  align-items: start;
}
.principle-marker {
  font-family: var(--serif);
  font-size: 22px;
  color: var(--accent);
  margin-top: 2px;
}
.principle h4 {
  font-size: 18px;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 10px;
}
.principle p {
  font-size: 15px;
  color: var(--fg-muted);
  line-height: 1.7;
}

/* Closing */
.closing {
  max-width: 1200px;
  margin: 0 auto;
  padding: clamp(64px, 8vw, 100px) clamp(24px, 5vw, 80px);
}
.closing-statement {
  font-family: var(--serif);
  font-size: clamp(20px, 3vw, 28px);
  line-height: 1.6;
  color: var(--fg-muted);
  max-width: 760px;
  font-style: italic;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px clamp(24px, 5vw, 80px);
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.footer-copy {
  font-size: 13px;
  color: var(--fg-muted);
}

/* Responsive */
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; gap: 48px; }
  .hero-visual { display: none; }
  .loop-diagram { grid-template-columns: 1fr; }
  .loop-arrow { display: none; }
  .math-grid { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  .hero-meta { gap: 16px; }
  .meta-value { font-size: 18px; }
  .principle { grid-template-columns: 1fr; }
  .principle-marker { display: none; }
  .footer-inner { flex-direction: column; gap: 12px; align-items: flex-start; }
}