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

:root {
  --bg: #fafaf9;
  --text: #1c1917;
  --accent: #059669;
  --accent-light: #d1fae5;
  --muted: #78716c;
}

body {
  font-family: system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  border-bottom: 1px solid #e7e5e4;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--accent);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: var(--text);
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--accent);
}

main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

.hero {
  text-align: center;
  padding: 4rem 0;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.hero p {
  font-size: 1.25rem;
  color: var(--muted);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.cta {
  display: inline-block;
  background: var(--accent);
  color: white;
  padding: 0.75rem 2rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
}

.cta:hover {
  opacity: 0.9;
}

.chapters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 3rem;
}

.chapter-card {
  background: white;
  border: 1px solid #e7e5e4;
  border-radius: 12px;
  padding: 1.5rem;
}

.chapter-card h3 {
  margin-bottom: 0.5rem;
}

.chapter-card p {
  color: var(--muted);
  font-size: 0.9rem;
}

footer {
  text-align: center;
  padding: 2rem;
  margin-top: 4rem;
  border-top: 1px solid #e7e5e4;
  color: var(--muted);
  font-size: 0.9rem;
}

.disclaimer {
  font-size: 0.8rem;
  margin-top: 0.5rem;
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }
  
  .nav {
    padding: 1rem;
  }
  
  .nav-links {
    gap: 1rem;
  }
}