:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #111118;
  --bg-card: #16161f;
  --bg-accent: #1c1c28;
  --text-primary: #f0f0f5;
  --text-secondary: #9494a8;
  --text-muted: #6b6b80;
  --accent: #4ade80;
  --accent-dim: rgba(74, 222, 128, 0.12);
  --accent-glow: rgba(74, 222, 128, 0.25);
  --border: rgba(255, 255, 255, 0.06);
  --radius: 12px;
  --radius-sm: 8px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: 'DM Sans', system-ui, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
  font-family: 'Space Grotesk', system-ui, sans-serif;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

/* ===================== HERO ===================== */
.hero {
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  background:
    radial-gradient(ellipse 60% 50% at 50% 0%, rgba(74, 222, 128, 0.08) 0%, transparent 70%),
    var(--bg-primary);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 400px;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.hero-inner {
  max-width: 780px;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-dim);
  border: 1px solid rgba(74, 222, 128, 0.15);
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 32px;
}

.hero h1 {
  font-size: clamp(2.4rem, 6vw, 4.2rem);
  font-weight: 700;
  margin-bottom: 24px;
}

.hero h1 .accent {
  color: var(--accent);
}

.lede {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0 auto 48px;
  line-height: 1.7;
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  padding: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.stat {
  text-align: center;
}

.stat-number {
  display: block;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 8px;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.stat-divider {
  width: 1px;
  height: 48px;
  background: var(--border);
}

/* ===================== PROBLEM ===================== */
.problem {
  padding: 100px 24px;
  background: var(--bg-secondary);
}

.problem-inner {
  max-width: 960px;
  margin: 0 auto;
}

.problem h2 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  margin-bottom: 48px;
  text-align: center;
}

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

.problem-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
}

.problem-icon {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 16px;
  opacity: 0.6;
}

.problem-card h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.problem-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===================== FEATURES ===================== */
.features {
  padding: 100px 24px;
  background: var(--bg-primary);
}

.features-inner {
  max-width: 960px;
  margin: 0 auto;
}

.features h2 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  margin-bottom: 12px;
  text-align: center;
}

.features-subtitle {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 48px;
  font-size: 1.05rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: border-color 0.2s;
}

.feature-card:hover {
  border-color: rgba(74, 222, 128, 0.2);
}

.feature-highlight {
  grid-column: 1 / -1;
  background: linear-gradient(135deg, var(--bg-card) 0%, rgba(74, 222, 128, 0.04) 100%);
  border-color: rgba(74, 222, 128, 0.12);
}

.feature-tag {
  display: inline-block;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 3px 10px;
  border-radius: 4px;
  margin-bottom: 14px;
}

.feature-card h3 {
  font-size: 1.2rem;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ===================== MATH ===================== */
.math {
  padding: 100px 24px;
  background: var(--bg-secondary);
}

.math-inner {
  max-width: 560px;
  margin: 0 auto;
}

.math h2 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  margin-bottom: 40px;
  text-align: center;
}

.math-example {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
}

.math-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
}

.math-row:last-child {
  border-bottom: none;
}

.math-label {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.math-value {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
}

.math-total {
  padding-top: 20px;
  margin-top: 6px;
  border-top: 2px solid var(--accent);
  border-bottom: none;
}

.math-total .math-label {
  color: var(--text-primary);
  font-weight: 500;
}

.math-total .math-value {
  color: var(--accent);
  font-size: 1.4rem;
}

.math-note {
  margin-top: 24px;
  font-size: 0.85rem;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.6;
}

/* ===================== CLOSING ===================== */
.closing {
  padding: 120px 24px;
  background:
    radial-gradient(ellipse 60% 40% at 50% 100%, rgba(74, 222, 128, 0.06) 0%, transparent 70%),
    var(--bg-primary);
  text-align: center;
}

.closing-inner {
  max-width: 700px;
  margin: 0 auto;
}

.closing h2 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  margin-bottom: 20px;
}

.closing p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 40px;
}

.closing-verticals {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

.vertical-tag {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-accent);
  border: 1px solid var(--border);
  padding: 8px 18px;
  border-radius: 100px;
}

/* ===================== FOOTER ===================== */
.site-footer {
  padding: 32px 24px;
  background: var(--bg-primary);
  border-top: 1px solid var(--border);
}

.footer-inner {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-brand {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.footer-copy {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ===================== RESPONSIVE ===================== */
@media (max-width: 768px) {
  .hero {
    min-height: auto;
    padding: 60px 20px 80px;
  }

  .hero-stats {
    flex-direction: column;
    gap: 24px;
    padding: 24px;
  }

  .stat-divider {
    width: 48px;
    height: 1px;
  }

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

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

  .feature-highlight {
    grid-column: auto;
  }

  .problem,
  .features,
  .math,
  .closing {
    padding: 60px 20px;
  }

  .closing-verticals {
    gap: 8px;
  }

  .vertical-tag {
    font-size: 0.8rem;
    padding: 6px 14px;
  }
}