body {
  margin: 40px auto;
  max-width: 650px;
  line-height: 1.6;
  font-size: 18px;
  color: #444;
  padding: 0 10px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
}

h1,
h2,
h3 {
  line-height: 1.2;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}
a {
  color: #007bff;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}