:root {
  --bg-color: #ffffff;
  --text-color: #222222;
  --accent-color: #0066cc;
  --secondary-bg: #f4f4f4;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #1a1a1a;
    --text-color: #f0f0f0;
    --accent-color: #4da3ff;
    --secondary-bg: #2d2d2d;
  }
}

body {
  font-family: system-ui, -apple-system, sans-serif;
  line-height: 1.6;
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: background-color 0.3s, color 0.3s;
}

h1, h2, h3 {
  color: var(--accent-color);
}

a {
  color: var(--accent-color);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

summary {
  -webkit-user-select: none;
  -ms-user-select: none;
  user-select: none;
}