:root {
  --bg: #0D0D0F;
  --bg-card: #16161A;
  --bg-elevated: #1C1C22;
  --fg: #E8E6E1;
  --fg-muted: #9B9A97;
  --accent: #F5A623;
  --accent-glow: rgba(245, 166, 35, 0.15);
  --accent-bright: #FFB940;
  --border: rgba(255, 255, 255, 0.06);
  --font-display: 'Syne', 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);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ===== HERO ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  background:
    radial-gradient(ellipse 60% 50% at 50% 0%, rgba(245, 166, 35, 0.08) 0%, transparent 70%),
    var(--bg);
}

.hero-inner {
  max-width: 820px;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  border: 1px solid var(--accent);
  border-radius: 100px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 32px;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 6.5vw, 5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--fg);
  margin-bottom: 24px;
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--fg-muted);
  max-width: 580px;
  margin: 0 auto 56px;
  line-height: 1.7;
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
}

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

.stat-number {
  font-family: var(--font-display);
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--fg-muted);
  max-width: 160px;
  text-align: center;
  line-height: 1.4;
}

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

/* ===== PROBLEM ===== */
.problem {
  padding: 120px 24px;
  background: var(--bg);
}

.problem-inner {
  max-width: 1000px;
  margin: 0 auto;
}

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

.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: 16px;
  padding: 36px 28px;
}

.problem-icon {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 20px;
  letter-spacing: 0.05em;
}

.problem-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--fg);
}

.problem-card p {
  font-size: 0.95rem;
  color: var(--fg-muted);
  line-height: 1.65;
}

/* ===== HOW IT WORKS ===== */
.how {
  padding: 120px 24px;
  background: var(--bg-card);
}

.how-inner {
  max-width: 720px;
  margin: 0 auto;
}

.how h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 64px;
  max-width: 540px;
}

.how-steps {
  display: flex;
  flex-direction: column;
  gap: 0;
  position: relative;
}

.step {
  display: flex;
  gap: 32px;
  padding-bottom: 48px;
  position: relative;
}

.step:last-child { padding-bottom: 0; }

.step::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 24px;
  bottom: 0;
  width: 1px;
  background: linear-gradient(to bottom, var(--accent), transparent);
}

.step:last-child::before { display: none; }

.step-marker {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 20px var(--accent-glow);
  position: relative;
  z-index: 1;
}

.step-content h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--fg);
}

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

/* ===== MATH ===== */
.math {
  padding: 120px 24px;
  background: var(--bg);
}

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

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

.math-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  margin-bottom: 32px;
}

.math-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 28px;
  border-bottom: 1px solid var(--border);
}

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

.math-row.highlight {
  background: var(--accent-glow);
}

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

.math-value {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--fg);
}

.math-row.highlight .math-label {
  color: var(--fg);
}

.math-row.highlight .math-value {
  color: var(--accent);
  font-size: 1.5rem;
}

.math-note {
  font-size: 0.95rem;
  color: var(--fg-muted);
  line-height: 1.7;
}

/* ===== CLOSING ===== */
.closing {
  padding: 120px 24px;
  text-align: center;
  background:
    radial-gradient(ellipse 50% 60% at 50% 100%, rgba(245, 166, 35, 0.06) 0%, transparent 70%),
    var(--bg-card);
}

.closing-inner {
  max-width: 620px;
  margin: 0 auto;
}

.closing h2 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.closing p {
  font-size: 1.05rem;
  color: var(--fg-muted);
  line-height: 1.75;
  margin-bottom: 36px;
}

.closing-ctas {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.cta-demo {
  display: inline-flex;
  align-items: center;
  padding: 13px 26px;
  border: 1px solid rgba(255,255,255,0.15);
  color: var(--fg);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  border-radius: 8px;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.cta-demo:hover {
  border-color: rgba(255,255,255,0.35);
  color: #fff;
}

.cta-start {
  display: inline-flex;
  align-items: center;
  padding: 13px 26px;
  background: var(--accent);
  color: #0D0D0F;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  border-radius: 8px;
  transition: background 0.2s ease, transform 0.15s ease;
}

.cta-start:hover {
  background: var(--accent-bright);
  transform: translateY(-1px);
}

/* ===== SITE NAV ===== */
.site-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 32px;
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13,13,15,0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--fg);
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-link-ghost {
  padding: 9px 18px;
  color: var(--fg-muted);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: 6px;
  transition: color 0.2s ease, background 0.2s ease;
}

.nav-link-ghost:hover {
  color: var(--fg);
  background: rgba(255,255,255,0.05);
}

.nav-link-cta {
  padding: 9px 20px;
  background: var(--accent);
  color: #0D0D0F;
  font-size: 0.88rem;
  font-weight: 700;
  text-decoration: none;
  border-radius: 6px;
  transition: background 0.2s ease;
}

.nav-link-cta:hover {
  background: var(--accent-bright);
}

/* ===== HERO CTAS ===== */
.hero-ctas {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero-cta-primary {
  display: inline-flex;
  align-items: center;
  padding: 15px 30px;
  background: var(--accent);
  color: #0D0D0F;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 1rem;
  text-decoration: none;
  border-radius: 8px;
  transition: background 0.2s ease, transform 0.15s ease;
}

.hero-cta-primary:hover {
  background: var(--accent-bright);
  transform: translateY(-1px);
}

.hero-cta-secondary {
  display: inline-flex;
  align-items: center;
  padding: 15px 30px;
  border: 1px solid rgba(255,255,255,0.15);
  color: var(--fg);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  border-radius: 8px;
  transition: border-color 0.2s ease;
}

.hero-cta-secondary:hover {
  border-color: rgba(255,255,255,0.35);
}

/* ===== FOOTER ===== */
.site-footer {
  padding: 40px 24px;
  border-top: 1px solid var(--border);
  background: var(--bg);
}

.footer-inner {
  max-width: 1000px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

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

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .problem-grid {
    grid-template-columns: 1fr;
  }

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

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

  .hero {
    padding: 60px 20px;
    min-height: auto;
  }

  .problem,
  .how,
  .math,
  .closing {
    padding: 80px 20px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }

  .math-row {
    padding: 16px 20px;
  }

  .math-value {
    font-size: 1.1rem;
  }

  .math-row.highlight .math-value {
    font-size: 1.3rem;
  }
}