:root {
  --bg: #0d1117;
  --surface: #161b22;
  --surface-2: #21262d;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #7d8590;
  --accent: #39FF85;
  --accent-dim: rgba(57, 255, 133, 0.12);
  --accent-2: #58a6ff;
  --tag-bg: rgba(57, 255, 133, 0.08);
  --error: #f85149;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'DM Sans', system-ui, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Navbar */
.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 48px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(12px);
  z-index: 100;
}
.nav-brand { display: flex; align-items: center; gap: 8px; }
.brand-mark { color: var(--accent); font-size: 18px; }
.brand-name {
  font-family: 'Fraunces', serif;
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
}
.nav-links { display: flex; align-items: center; gap: 32px; }
.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }
.nav-cta {
  color: var(--accent) !important;
  background: var(--accent-dim);
  border: 1px solid rgba(57, 255, 133, 0.25);
  padding: 8px 16px;
  border-radius: 6px;
  font-weight: 600;
  transition: background 0.2s, border-color 0.2s;
}
.nav-cta:hover {
  background: rgba(57, 255, 133, 0.2) !important;
  border-color: rgba(57, 255, 133, 0.4);
}

/* Hero */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  padding: 96px 48px 80px;
  border-bottom: 1px solid var(--border);
  max-width: 1200px;
  margin: 0 auto;
}
.hero-text {}
.hero-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 20px;
}
.hero-headline {
  font-family: 'Fraunces', serif;
  font-size: clamp(44px, 5.5vw, 72px);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 24px;
}
.headline-accent { color: var(--accent); }
.hero-sub {
  font-size: 17px;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 460px;
  margin-bottom: 36px;
}
.hero-cta { display: flex; flex-direction: column; gap: 12px; align-items: flex-start; }
.cta-button {
  display: inline-block;
  background: var(--accent);
  color: #0d1117;
  font-weight: 700;
  font-size: 16px;
  padding: 14px 28px;
  border-radius: 8px;
  text-decoration: none;
  letter-spacing: 0.01em;
  transition: background 0.2s, transform 0.15s;
}
.cta-button:hover { background: #2de072; transform: translateY(-1px); }
.cta-note { font-size: 13px; color: var(--text-muted); }

/* Stack Card */
.stack-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
  box-shadow: 0 0 60px rgba(57, 255, 133, 0.05);
}
.stack-header {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 20px;
}
.stack-layer {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: 8px;
  margin-bottom: 8px;
  background: var(--surface-2);
  border: 1px solid var(--border);
}
.layer-icon { color: var(--accent); font-size: 14px; }
.layer-label { flex: 1; font-size: 13px; font-weight: 500; color: var(--text); }
.stack-divider {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  text-align: center;
}
.stack-target {
  font-family: 'Fraunces', serif;
  font-size: 18px;
  font-weight: 700;
  color: var(--accent);
}

/* Problem Section */
.problem-section {
  padding: 96px 48px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}
.section-inner { max-width: 800px; margin: 0 auto; }
.problem-label { margin-bottom: 20px; }
.eyebrow-tag {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-dim);
  border: 1px solid rgba(57, 255, 133, 0.25);
  padding: 5px 12px;
  border-radius: 4px;
}
.problem-headline {
  font-family: 'Fraunces', serif;
  font-size: clamp(32px, 4vw, 52px);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.025em;
  color: var(--text);
  margin-bottom: 24px;
}
.problem-body {
  font-size: 16px;
  color: var(--text-muted);
  margin-bottom: 40px;
}
.problem-stats {
  display: flex;
  gap: 32px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}
.problem-stat { flex: 1; min-width: 160px; }
.ps-number {
  font-family: 'Fraunces', serif;
  font-size: 48px;
  font-weight: 900;
  color: var(--accent);
  letter-spacing: -0.02em;
  line-height: 1;
  margin-bottom: 8px;
}
.ps-label { font-size: 13px; color: var(--text-muted); line-height: 1.4; }
.problem-cta {
  font-size: 16px;
  color: var(--text-muted);
  font-style: italic;
}

/* Models Section */
.models-section {
  padding: 96px 48px;
  border-bottom: 1px solid var(--border);
  max-width: 1200px;
  margin: 0 auto;
}
.section-header { text-align: center; margin-bottom: 56px; }
.section-eyebrow {
  display: block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
}
.section-title {
  font-family: 'Fraunces', serif;
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 16px;
}
.section-desc {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto;
}
.models-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.model-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px;
  transition: border-color 0.2s;
}
.model-card:hover { border-color: rgba(57, 255, 133, 0.3); }
.model-icon { font-size: 28px; color: var(--accent); margin-bottom: 16px; }
.model-name {
  font-family: 'Fraunces', serif;
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}
.model-desc {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 16px;
}
.model-meta { display: flex; gap: 8px; flex-wrap: wrap; }
.meta-tag {
  font-size: 11px;
  font-weight: 600;
  background: var(--tag-bg);
  color: var(--accent);
  border: 1px solid rgba(57, 255, 133, 0.15);
  padding: 3px 8px;
  border-radius: 4px;
}

/* Pathway */
.pathway-section {
  padding: 96px 48px;
  border-bottom: 1px solid var(--border);
  max-width: 1200px;
  margin: 0 auto;
}
.pathway-timeline { max-width: 640px; margin: 0 auto; }
.pathway-step { display: flex; gap: 28px; align-items: flex-start; }
.step-num {
  font-family: 'Fraunces', serif;
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-dim);
  border: 1px solid rgba(57, 255, 133, 0.2);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 4px;
}
.step-body { padding-bottom: 32px; }
.step-title {
  font-family: 'Fraunces', serif;
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}
.step-desc { font-size: 14px; color: var(--text-muted); line-height: 1.7; }
.pathway-connector {
  width: 2px;
  height: 28px;
  background: var(--border);
  margin-left: 19px;
  margin-bottom: 28px;
}
.pathway-note {
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 48px;
  font-style: italic;
}

/* Manifesto */
.manifesto-section {
  padding: 96px 48px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}
.manifesto-inner { max-width: 760px; margin: 0 auto; text-align: center; }
.manifesto-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 28px;
}
.manifesto-quote {
  font-family: 'Fraunces', serif;
  font-size: clamp(20px, 2.5vw, 28px);
  font-weight: 400;
  font-style: italic;
  color: var(--text);
  line-height: 1.4;
  margin-bottom: 32px;
  letter-spacing: -0.01em;
}
.manifesto-body {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 20px;
}

/* Closing / Signup */
.closing-section {
  padding: 96px 48px;
  border-bottom: 1px solid var(--border);
}
.closing-inner { text-align: center; max-width: 640px; margin: 0 auto; }
.closing-headline {
  font-family: 'Fraunces', serif;
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 900;
  color: var(--text);
  line-height: 1.15;
  letter-spacing: -0.025em;
  margin-bottom: 20px;
}
.closing-sub {
  font-size: 16px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 40px;
}

/* Signup Form */
.signup-form { width: 100%; }
.form-row {
  display: flex;
  gap: 10px;
  max-width: 480px;
  margin: 0 auto 12px;
}
.form-input {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 15px;
  padding: 14px 16px;
  font-family: 'DM Sans', system-ui, sans-serif;
  transition: border-color 0.2s;
  outline: none;
}
.form-input:focus { border-color: var(--accent); }
.form-input::placeholder { color: var(--text-muted); }
.form-submit {
  background: var(--accent);
  color: #0d1117;
  border: none;
  border-radius: 8px;
  font-weight: 700;
  font-size: 15px;
  padding: 14px 24px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s, transform 0.15s;
  font-family: 'DM Sans', system-ui, sans-serif;
}
.form-submit:hover:not(:disabled) { background: #2de072; transform: translateY(-1px); }
.form-submit:disabled { opacity: 0.7; cursor: not-allowed; }
.form-note { font-size: 13px; color: var(--text-muted); margin-bottom: 8px; }
.form-success { color: var(--accent); font-size: 15px; font-weight: 600; margin-top: 8px; }
.form-error { color: var(--error); font-size: 14px; margin-top: 8px; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 48px;
  text-align: center;
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}
.footer-tagline {
  font-family: 'Fraunces', serif;
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 6px;
}
.footer-note { font-size: 12px; color: var(--text-muted); opacity: 0.6; }

/* Responsive */
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; gap: 40px; padding: 64px 24px 56px; }
  .hero-visual { order: -1; }
  .models-grid { grid-template-columns: 1fr 1fr; }
  .problem-stats { gap: 24px; }
  .form-row { flex-direction: column; }
  .form-submit { width: 100%; }
  .navbar { padding: 16px 24px; }
  .nav-links { display: none; }
}
@media (max-width: 600px) {
  .models-grid { grid-template-columns: 1fr; }
  .problem-section,
  .models-section,
  .pathway-section,
  .manifesto-section,
  .closing-section { padding: 64px 24px; }
  .closing-section { padding-bottom: 80px; }
}