:root {
  --bg: #0C0F12;
  --bg-alt: #141920;
  --fg: #E8ECF1;
  --fg-muted: #8B95A5;
  --accent: #FF6B35;
  --accent-glow: rgba(255, 107, 53, 0.15);
  --accent-bright: #FF8C5A;
  --green: #34D399;
  --border: rgba(255, 255, 255, 0.06);
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'DM Sans', sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

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

/* === HERO === */
.hero {
  min-height: 90vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 80px 24px 60px;
  max-width: 900px;
  margin: 0 auto;
}

.hero-badge {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 32px;
  padding: 8px 16px;
  background: var(--accent-glow);
  border: 1px solid rgba(255, 107, 53, 0.2);
  border-radius: 100px;
  display: inline-block;
  width: fit-content;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 28px;
  color: var(--fg);
}

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

.hero-sub {
  font-size: 1.15rem;
  line-height: 1.65;
  color: var(--fg-muted);
  max-width: 640px;
  margin-bottom: 56px;
}

.hero-stats {
  display: flex;
  gap: 32px;
  align-items: center;
  padding: 32px 0;
  border-top: 1px solid var(--border);
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.stat-number {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--fg);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--fg-muted);
  max-width: 160px;
}

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

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

.problem-inner {
  max-width: 900px;
  margin: 0 auto;
}

.problem-label {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 20px;
}

.problem h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 48px;
  max-width: 700px;
}

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

.problem-card {
  padding: 32px 28px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: border-color 0.2s;
}

.problem-card:hover {
  border-color: rgba(255, 107, 53, 0.3);
}

.problem-icon {
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--accent);
  padding: 6px 12px;
  background: var(--accent-glow);
  border-radius: 6px;
  display: inline-block;
  margin-bottom: 20px;
}

.problem-card h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--fg);
}

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

/* === KIT === */
.kit {
  padding: 100px 24px;
}

.kit-inner {
  max-width: 900px;
  margin: 0 auto;
}

.kit-label {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 20px;
}

.kit h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 56px;
  max-width: 600px;
}

.kit-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.kit-item {
  padding: 32px 28px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 12px;
  position: relative;
  transition: border-color 0.2s;
}

.kit-item:hover {
  border-color: rgba(255, 107, 53, 0.25);
}

.kit-num {
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 700;
  color: rgba(255, 107, 53, 0.4);
  margin-bottom: 16px;
}

.kit-item h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--fg);
}

.kit-item p {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--fg-muted);
}

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

.math-inner {
  max-width: 640px;
  margin: 0 auto;
}

.math-label {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 20px;
}

.math h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 48px;
}

.math-table {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-bottom: 32px;
}

.math-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
}

.math-row.total {
  border-bottom: none;
  padding-top: 24px;
  margin-top: 8px;
  border-top: 2px solid var(--accent);
}

.math-left {
  font-size: 1rem;
  color: var(--fg-muted);
}

.math-right {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--fg);
}

.math-right.accent {
  color: var(--accent);
}

.math-row.total .math-left {
  color: var(--fg);
  font-weight: 600;
}

.math-row.total .math-right {
  color: var(--green);
  font-size: 1.6rem;
}

.math-note {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--fg-muted);
  padding-top: 8px;
}

/* === CLOSING === */
.closing {
  padding: 100px 24px;
  text-align: center;
}

.closing-inner {
  max-width: 800px;
  margin: 0 auto;
}

.closing h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}

.closing-sub {
  font-size: 1.1rem;
  line-height: 1.65;
  color: var(--fg-muted);
  max-width: 560px;
  margin: 0 auto 56px;
}

.closing-tiers {
  display: flex;
  gap: 20px;
  justify-content: center;
}

.tier {
  padding: 32px 28px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 12px;
  min-width: 180px;
  transition: border-color 0.2s;
}

.tier:hover {
  border-color: rgba(255, 255, 255, 0.12);
}

.tier.featured {
  border-color: var(--accent);
  background: linear-gradient(180deg, rgba(255, 107, 53, 0.08) 0%, var(--bg-alt) 100%);
  position: relative;
}

.tier-name {
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--fg-muted);
  margin-bottom: 8px;
}

.tier.featured .tier-name {
  color: var(--accent);
}

.tier-price {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--fg);
  margin-bottom: 8px;
}

.tier-desc {
  font-size: 0.85rem;
  color: var(--fg-muted);
  line-height: 1.5;
}

/* === FOOTER === */
.footer {
  padding: 48px 24px;
  border-top: 1px solid var(--border);
}

.footer-inner {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--fg);
}

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

/* === RESPONSIVE === */
@media (max-width: 768px) {
  .hero {
    min-height: auto;
    padding: 60px 20px 40px;
  }

  .hero-stats {
    flex-direction: column;
    align-items: flex-start;
    gap: 24px;
  }

  .stat-divider {
    display: none;
  }

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

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

  .closing-tiers {
    flex-direction: column;
    align-items: center;
  }

  .tier {
    width: 100%;
    max-width: 300px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }

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

@media (max-width: 480px) {
  .hero h1 {
    font-size: 2.4rem;
  }

  .problem h2,
  .kit h2,
  .math h2 {
    font-size: 1.6rem;
  }

  .closing h2 {
    font-size: 1.8rem;
  }
}