:root {
  --bg: #0b0d14;
  --fg: #e8e9ed;
  --fg-muted: #8b8fa8;
  --accent: #F5C518;
  --accent-dim: #a88610;
  --surface: #141720;
  --surface-2: #1c1f2e;
  --border: #222538;
  --font-display: 'Syne', sans-serif;
  --font-body: 'DM Sans', sans-serif;
}

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

html { font-size: 16px; scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* NAV */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 13, 20, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 18px 32px;
  display: flex;
  align-items: baseline;
  gap: 16px;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
}
.nav-tagline {
  font-size: 0.8rem;
  color: var(--fg-muted);
  font-weight: 300;
}

/* HERO */
.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 80px 32px 60px;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.hero-headline {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 4.5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--fg);
}
.hero-sub {
  margin-top: 24px;
  font-size: 1.1rem;
  color: var(--fg-muted);
  line-height: 1.65;
  max-width: 440px;
}
.hero-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.algo-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  width: 100%;
  max-width: 400px;
}
.algo-card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 8px 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 120px;
}
.algo-card-bar {
  width: 70%;
  background: var(--surface-2);
  border-radius: 4px;
  margin-bottom: 8px;
  flex: 1;
  max-height: 70px;
  transition: background 0.2s;
}
.algo-card-bar.winner {
  background: var(--accent);
  box-shadow: 0 0 20px rgba(245, 197, 24, 0.35);
}
.algo-label {
  font-size: 0.62rem;
  font-weight: 500;
  color: var(--fg-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  text-align: center;
  margin-top: 6px;
}
.algo-winner-tag {
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: #0b0d14;
  font-size: 0.55rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 3px 7px;
  border-radius: 20px;
  white-space: nowrap;
}
.hero-visual-caption {
  margin-top: 12px;
  font-size: 0.72rem;
  color: var(--fg-muted);
  text-align: center;
}

/* STATS */
.stats {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.stats-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 32px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}
.stat { text-align: center; }
.stat-number {
  font-family: var(--font-display);
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.04em;
  line-height: 1;
}
.stat-label {
  margin-top: 8px;
  font-size: 0.8rem;
  color: var(--fg-muted);
  line-height: 1.4;
}

/* HOW */
.how {
  max-width: 1200px;
  margin: 0 auto;
  padding: 96px 32px;
}
.how-header { margin-bottom: 56px; }
.section-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 12px;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.phase-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.phase {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 32px;
  padding: 40px 0;
  border-bottom: 1px solid var(--border);
  align-items: start;
}
.phase:last-child { border-bottom: none; }
.phase-num {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.04em;
  line-height: 1;
  padding-top: 4px;
}
.phase-name {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}
.phase-desc {
  color: var(--fg-muted);
  font-size: 0.95rem;
  line-height: 1.65;
}

/* NICHES */
.niches {
  background: var(--surface);
  padding: 96px 32px;
}
.niches-header {
  max-width: 1200px;
  margin: 0 auto 56px;
}
.niches-sub {
  margin-top: 12px;
  color: var(--fg-muted);
  font-size: 1rem;
  max-width: 520px;
}
.niche-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
}
.niche-card {
  background: var(--bg);
  padding: 32px 28px;
  transition: background 0.2s;
}
.niche-card:hover { background: var(--surface-2); }
.niche-icon {
  font-size: 1.2rem;
  color: var(--accent);
  margin-bottom: 16px;
}
.niche-card h3 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}
.niche-card p {
  font-size: 0.85rem;
  color: var(--fg-muted);
  line-height: 1.6;
}

/* MATH */
.math {
  max-width: 1200px;
  margin: 0 auto;
  padding: 96px 32px;
}
.math-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}
.math-visual {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0;
}
.math-rule {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.math-arrow {
  padding: 4px 0 4px 32px;
  align-self: flex-start;
}
.math-lbl {
  font-size: 0.72rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--fg-muted);
}
.math-val {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.02em;
}
.math-scenarios {
  margin-top: 4px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  width: 100%;
}
.scenario {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.scenario-comm {
  font-size: 0.72rem;
  color: var(--fg-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.scenario-conv {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--fg);
}
.scenario-daily {
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 500;
}
.math-text h2 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 2.5vw, 2.2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 24px;
}
.math-text p {
  color: var(--fg-muted);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 16px;
}
.math-insight {
  background: var(--surface);
  border-left: 3px solid var(--accent);
  padding: 16px 20px;
  border-radius: 0 10px 10px 0;
  font-size: 0.88rem;
  color: var(--fg-muted);
  font-style: italic;
  margin-top: 8px;
}

/* CLOSING */
.closing {
  background: var(--surface);
  border-top: 1px solid var(--border);
}
.closing-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 96px 32px;
  text-align: center;
}
.closing-headline {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3.5vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 24px;
}
.closing-body {
  color: var(--fg-muted);
  font-size: 1.05rem;
  line-height: 1.7;
  max-width: 540px;
  margin: 0 auto 40px;
}
.closing-cta {
  display: inline-block;
  padding: 14px 32px;
  background: var(--accent);
  color: #0b0d14;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.9rem;
  letter-spacing: 0.02em;
}

/* FOOTER */
.footer {
  border-top: 1px solid var(--border);
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 32px;
}
.footer-logo {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent);
}
.footer-desc {
  margin-top: 6px;
  font-size: 0.8rem;
  color: var(--fg-muted);
  max-width: 320px;
}
.footer-links {
  font-size: 0.75rem;
  color: var(--fg-muted);
}

/* RESPONSIVE */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 48px; }
  .hero-visual { display: none; }
  .stats-inner { grid-template-columns: repeat(2, 1fr); }
  .math-inner { grid-template-columns: 1fr; gap: 48px; }
  .niche-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .stats-inner { grid-template-columns: 1fr 1fr; gap: 24px; }
  .niche-grid { grid-template-columns: 1fr; }
  .phase { grid-template-columns: 40px 1fr; gap: 16px; }
  .math-scenarios { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}