body {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

pre {
  background-color: #dfdfdf;
  border-radius: 5px;
  overflow-x: auto;
}

img {
  max-width: 1200px;
}

#toc li {
  padding-bottom: 8px;
}

.centered {
  margin: 0 auto;
}