body {
  font-family: sans-serif;
  margin: 0;
  line-height: 1.6;
}

header, main, footer {
  max-width: 800px;
  margin: auto;
  padding: 1rem;
}

header {
  border-bottom: 1px solid #ddd;
}

section {
  margin-bottom: 2rem;
}