:root {
  --color-bg: #fafafa;
  --color-text: #222;
  --color-accent: #2f6f4f;
  --color-muted: #666;
  --max-width: 720px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

.site-header {
  padding: 2rem 1.5rem 1rem;
  text-align: center;
  border-bottom: 1px solid #e0e0e0;
}

.site-header h1 {
  margin: 0 0 0.5rem;
}

nav a {
  margin: 0 0.75rem;
  color: var(--color-accent);
  text-decoration: none;
  font-weight: 600;
}

nav a:hover {
  text-decoration: underline;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.hero {
  text-align: center;
  padding: 2rem 0;
}

section {
  margin-bottom: 2.5rem;
}

footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--color-muted);
  font-size: 0.9rem;
}

a {
  color: var(--color-accent);
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #1a1a1a;
    --color-text: #eee;
    --color-accent: #7fd1a7;
    --color-muted: #aaa;
  }
  .site-header {
    border-bottom-color: #333;
  }
}