body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  background-color: #fff;
  color: #222;
  transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark-mode {
  background-color: #111;
  color: #eee;
}

a {
  color: #2a7ae2;
}

details summary {
  cursor: pointer;
  font-weight: bold;
  margin-top: 20px;
}

.toggle-dark {
  position: fixed;
  top: 10px;
  right: 20px;
  cursor: pointer;
  font-size: 16px;
  background: #ddd;
  padding: 6px 10px;
  border-radius: 4px;
}

body.dark-mode .toggle-dark {
  background: #333;
  color: #fff;
}

/* Mobile-friendly enhancements */
body {
  margin: 0;
  padding: 0 1rem;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
}

main {
  max-width: 800px;
  margin: auto;
  padding: 1rem 0;
}

nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
}

nav a {
  padding: 0.5rem 1rem;
  text-decoration: none;
  background: #eee;
  border-radius: 5px;
  font-weight: bold;
  color: #000;
}

th, td {
  padding: 4pt;
}

@media (max-width: 600px) {
  body {
    font-size: 15px;
    padding: 0 0.5rem;
  }

  nav a {
    font-size: 14px;
    padding: 0.4rem 0.8rem;
  }
}