:root {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: #161d2e;
  --fg-primary: #f0f2f5;
  --fg-secondary: #94a3b8;
  --fg-muted: #64748b;
  --accent: #22d3ee;
  --accent-glow: rgba(34, 211, 238, 0.15);
  --accent-secondary: #a78bfa;
  --accent-warm: #f472b6;
  --border: rgba(148, 163, 184, 0.1);
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'DM Sans', sans-serif;
  --max-width: 1120px;
}

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

body {
  background: var(--bg-primary);
  color: var(--fg-primary);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* === HERO === */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  padding: 120px 0 100px;
  overflow: hidden;
}

.hero-bg-elements {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

.helix-strand {
  position: absolute;
  width: 2px;
  height: 100%;
  opacity: 0.07;
}

.strand-1 {
  left: 15%;
  background: linear-gradient(180deg, transparent, var(--accent), var(--accent-secondary), transparent);
  animation: helixDrift 12s ease-in-out infinite;
}

.strand-2 {
  right: 20%;
  background: linear-gradient(180deg, transparent, var(--accent-warm), var(--accent), transparent);
  animation: helixDrift 15s ease-in-out infinite reverse;
}

.glow-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.12;
}

.orb-1 {
  width: 500px;
  height: 500px;
  background: var(--accent);
  top: -100px;
  right: -100px;
  animation: orbFloat 20s ease-in-out infinite;
}

.orb-2 {
  width: 400px;
  height: 400px;
  background: var(--accent-secondary);
  bottom: -150px;
  left: -100px;
  animation: orbFloat 25s ease-in-out infinite reverse;
}

@keyframes helixDrift {
  0%, 100% { transform: translateX(0) scaleY(1); }
  50% { transform: translateX(30px) scaleY(1.05); }
}

@keyframes orbFloat {
  0%, 100% { transform: translate(0, 0); }
  33% { transform: translate(30px, -20px); }
  66% { transform: translate(-20px, 30px); }
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 100px;
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-glow);
  border: 1px solid rgba(34, 211, 238, 0.2);
  margin-bottom: 28px;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
  background: linear-gradient(135deg, var(--fg-primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.lede {
  font-size: 1.2rem;
  line-height: 1.7;
  color: var(--fg-secondary);
  max-width: 580px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-top: 36px;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 16px 32px;
  border-radius: 12px;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent) 0%, #0ea5e9 100%);
  color: #0a0e17;
  text-decoration: none;
  transition: opacity 0.2s ease, transform 0.15s ease;
  white-space: nowrap;
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-2px);
}

.hero-note {
  font-size: 0.85rem;
  color: var(--fg-muted);
}

/* === HOW IT WORKS === */
.how-it-works {
  padding: 120px 0;
  border-top: 1px solid var(--border);
}

.section-label {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
}

.how-it-works h2,
.features h2,
.science h2,
.closing h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin-bottom: 56px;
  color: var(--fg-primary);
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
}

.step {
  position: relative;
}

.step-number {
  font-family: var(--font-display);
  font-size: 4rem;
  font-weight: 700;
  color: var(--accent);
  opacity: 0.15;
  line-height: 1;
  margin-bottom: 16px;
}

.step-content h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--fg-primary);
}

.step-content p {
  color: var(--fg-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* === FEATURES === */
.features {
  padding: 120px 0;
  background: var(--bg-secondary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 36px 32px;
  transition: border-color 0.3s ease, transform 0.3s ease;
}

.feature-card:hover {
  border-color: rgba(34, 211, 238, 0.25);
  transform: translateY(-4px);
}

.feature-large {
  grid-column: span 3;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 24px;
  align-items: start;
  padding: 48px 40px;
  background: linear-gradient(135deg, var(--bg-card) 0%, rgba(34, 211, 238, 0.04) 100%);
  border-color: rgba(34, 211, 238, 0.15);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.feature-large .feature-icon {
  font-size: 2.5rem;
  margin-bottom: 0;
}

.feature-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--fg-primary);
}

.feature-card p {
  color: var(--fg-secondary);
  font-size: 0.92rem;
  line-height: 1.65;
}

/* === SCIENCE === */
.science {
  padding: 120px 0;
  border-top: 1px solid var(--border);
}

.science-content {
  max-width: 720px;
}

.science-content p {
  color: var(--fg-secondary);
  margin-bottom: 20px;
  font-size: 1.05rem;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 48px;
  padding-top: 40px;
  border-top: 1px solid var(--border);
}

.stat-number {
  display: block;
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 6px;
}

.stat-label {
  display: block;
  font-size: 0.85rem;
  color: var(--fg-muted);
  line-height: 1.4;
}

/* === CLOSING === */
.closing {
  padding: 140px 0;
  background: linear-gradient(180deg, var(--bg-primary) 0%, rgba(34, 211, 238, 0.03) 50%, var(--bg-primary) 100%);
  text-align: center;
}

.closing-content {
  max-width: 680px;
  margin: 0 auto;
}

.closing h2 {
  margin-bottom: 24px;
  background: linear-gradient(135deg, var(--fg-primary) 0%, var(--accent-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.closing p {
  color: var(--fg-secondary);
  font-size: 1.1rem;
  line-height: 1.8;
}

/* === FOOTER === */
.site-footer {
  padding: 60px 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--fg-primary);
  margin-bottom: 8px;
}

.footer-tagline {
  color: var(--fg-muted);
  font-size: 0.9rem;
}

/* === RESPONSIVE === */
@media (max-width: 768px) {
  .hero {
    min-height: auto;
    padding: 80px 0 60px;
  }

  .steps-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .feature-large {
    grid-column: span 1;
    grid-template-columns: 1fr;
  }

  .stat-row {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .how-it-works,
  .features,
  .science {
    padding: 80px 0;
  }

  .closing {
    padding: 80px 0;
  }

  .how-it-works h2,
  .features h2,
  .science h2,
  .closing h2 {
    margin-bottom: 36px;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 16px;
  }

  .container {
    padding: 0 16px;
  }

  .hero {
    padding: 60px 0 48px;
  }

  .feature-card {
    padding: 28px 24px;
  }

  .feature-large {
    padding: 32px 24px;
  }
}