body {
  font-family: Georgia, serif;
  max-width: 40rem;
  margin: 2rem auto;
  padding: 0 1.5rem;
  line-height: 1.6;
  color: #1a1a1a;
}

h1 {
  font-size: 1.75rem;
  border-bottom: 2px solid #ddd;
  padding-bottom: 0.35rem;
}

h2 {
  font-size: 1.15rem;
  margin-top: 1.5rem;
}

a {
  color: #0d47a1;
}

.topic {
  font-size: 0.9rem;
  color: #555;
  margin-bottom: 1rem;
}

ul.topics {
  list-style: none;
  padding: 0;
  margin: 0;
}

ul.topics li {
  margin: 0.65rem 0;
}

.series {
  font-size: 0.9rem;
  color: #444;
  border-left: 3px solid #0d47a1;
  padding-left: 0.75rem;
  margin: 1rem 0;
}

.back {
  margin-top: 2rem;
  font-size: 0.95rem;
}

footer {
  margin-top: 3rem;
  font-size: 0.85rem;
  color: #666;
}