/* === PrepLattice Theme === */
:root {
  --bg-deep: #0a1628;
  --bg-surface: #0f1d33;
  --bg-card: #142442;
  --fg: #e8ecf4;
  --fg-muted: #8899b3;
  --accent: #00d4aa;
  --accent-dim: rgba(0, 212, 170, 0.15);
  --warm: #ffb347;
  --warm-dim: rgba(255, 179, 71, 0.15);
  --border: rgba(255, 255, 255, 0.06);
  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;
}

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

body {
  background: var(--bg-deep);
  color: var(--fg);
  font-family: var(--font-body);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* Nav */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 22, 40, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.logo-mark {
  color: var(--accent);
  font-size: 1.4rem;
}
.logo-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: -0.02em;
}
.nav-tagline {
  color: var(--fg-muted);
  font-size: 0.85rem;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}
.nav-link {
  color: var(--fg-muted);
  font-size: 0.9rem;
  text-decoration: none;
  transition: color 0.15s;
}
.nav-link:hover { color: var(--fg); }

/* Hero */
.hero {
  position: relative;
  padding: 10rem 2rem 6rem;
  text-align: center;
  overflow: hidden;
}
.hero-inner {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}
.hero-glow {
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(0, 212, 170, 0.08) 0%, transparent 60%);
  pointer-events: none;
  z-index: 1;
}
.hero-stats-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}
.hero-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.stat-number {
  font-family: var(--font-display);
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.03em;
}
.stat-label {
  font-size: 0.8rem;
  color: var(--fg-muted);
  margin-top: 0.25rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border);
}
.hero-title {
  font-family: var(--font-display);
  font-size: 3.2rem;
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
}
.hero-accent {
  background: linear-gradient(135deg, var(--accent), var(--warm));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-lede {
  font-size: 1.2rem;
  color: var(--fg-muted);
  max-width: 650px;
  margin: 0 auto;
  line-height: 1.7;
}

/* Section Labels */
.section-label {
  font-family: var(--font-display);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 1rem;
}

/* Problem Section */
.problem {
  padding: 6rem 2rem;
  background: var(--bg-surface);
}
.problem-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.problem-title {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 3rem;
}
.problem-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}
.problem-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem 1.5rem;
}
.problem-icon {
  font-size: 1.8rem;
  margin-bottom: 1rem;
}
.problem-card h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}
.problem-card p {
  font-size: 0.9rem;
  color: var(--fg-muted);
  line-height: 1.6;
}

/* How It Works */
.how-it-works {
  padding: 6rem 2rem;
}
.hiw-inner {
  max-width: 900px;
  margin: 0 auto;
}
.hiw-title {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 3rem;
}
.hiw-steps {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}
.hiw-step {
  flex: 1;
  padding: 2rem;
  background: var(--bg-surface);
  border-radius: 12px;
  border: 1px solid var(--border);
}
.step-number {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  opacity: 0.5;
  margin-bottom: 1rem;
  display: block;
}
.hiw-step h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}
.hiw-step p {
  font-size: 0.9rem;
  color: var(--fg-muted);
  line-height: 1.6;
}
.hiw-connector {
  width: 40px;
  height: 2px;
  background: var(--accent);
  opacity: 0.3;
  margin-top: 3rem;
  flex-shrink: 0;
}

/* Exam Coverage */
.coverage {
  padding: 6rem 2rem;
  background: var(--bg-surface);
}
.coverage-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.coverage-title {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 3rem;
}
.coverage-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
}
.coverage-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  transition: border-color 0.2s;
}
.coverage-card:hover {
  border-color: rgba(0, 212, 170, 0.3);
}
.coverage-emoji {
  font-size: 1.6rem;
  margin-bottom: 0.75rem;
}
.coverage-card h3 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}
.coverage-card p {
  font-size: 0.8rem;
  color: var(--fg-muted);
  line-height: 1.5;
}
.coverage-note {
  text-align: center;
  margin-top: 2rem;
  color: var(--fg-muted);
  font-style: italic;
  font-size: 0.95rem;
}

/* Flywheel */
.flywheel {
  padding: 6rem 2rem;
}
.flywheel-inner {
  max-width: 1000px;
  margin: 0 auto;
}
.flywheel-title {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 2.5rem;
}
.flywheel-explanation {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}
.flywheel-big {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 600;
  line-height: 1.5;
  margin-bottom: 1.5rem;
  color: var(--warm);
}
.flywheel-text p {
  color: var(--fg-muted);
  margin-bottom: 1rem;
  font-size: 0.95rem;
}
.flywheel-diagram {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.fw-node {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 0.95rem;
}
.fw-node-1 { border-left: 3px solid var(--accent); }
.fw-node-2 { border-left: 3px solid #5b8def; }
.fw-node-3 { border-left: 3px solid var(--warm); }
.fw-node-4 { border-left: 3px solid #e06090; }
.fw-arrow {
  color: var(--fg-muted);
  opacity: 0.4;
  font-size: 1.2rem;
  padding-left: 1.5rem;
}

/* Manifesto */
.manifesto {
  padding: 8rem 2rem;
  background: linear-gradient(180deg, var(--bg-deep) 0%, var(--bg-surface) 100%);
  text-align: center;
}
.manifesto-inner {
  max-width: 750px;
  margin: 0 auto;
}
.manifesto-title {
  font-family: var(--font-display);
  font-size: 2.6rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 2rem;
  background: linear-gradient(135deg, var(--fg) 30%, var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.manifesto-text {
  font-size: 1.1rem;
  color: var(--fg-muted);
  line-height: 1.8;
}

/* Footer */
.footer {
  padding: 3rem 2rem;
  border-top: 1px solid var(--border);
  text-align: center;
}
.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.footer-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}
.footer-copy {
  color: var(--fg-muted);
  font-size: 0.85rem;
  margin-bottom: 0.5rem;
}
.footer-legal {
  color: var(--fg-muted);
  font-size: 0.75rem;
  opacity: 0.6;
}

/* Responsive */
@media (max-width: 768px) {
  .hero { padding: 8rem 1.5rem 4rem; }
  .hero-title { font-size: 2rem; }
  .hero-stats-row { flex-direction: column; gap: 1.5rem; }
  .stat-divider { width: 40px; height: 1px; }
  .stat-number { font-size: 1.8rem; }
  .problem-grid { grid-template-columns: 1fr 1fr; }
  .hiw-steps { flex-direction: column; }
  .hiw-connector { width: 2px; height: 20px; margin: 0 auto; }
  .coverage-grid { grid-template-columns: 1fr 1fr; }
  .flywheel-explanation { grid-template-columns: 1fr; }
  .manifesto-title { font-size: 1.8rem; }
  section { padding: 4rem 1.5rem; }
}
@media (max-width: 480px) {
  .problem-grid { grid-template-columns: 1fr; }
  .coverage-grid { grid-template-columns: 1fr; }
  .hero-title { font-size: 1.6rem; }
  .nav-tagline { display: none; }
}