body {
  margin: 40px auto;
  width: 95vw;
  max-width: 640px;
  line-height: 1.6;
  font-size: 18px;
  color: #444;
  font-family: "Lucida Console", "Courier New", monospace;
}

h1, h2, h3, h4, summary
{
  line-height: 1.2;
  font-family: "Lucida Console", "Courier New", monospace;
}