body {
  max-width: 650px;
  margin: 40px auto;
  padding: 0 10px;
  font:
    18px/1.5 -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    "Helvetica Neue",
    Arial,
    "Noto Sans",
    sans-serif,
    "Apple Color Emoji",
    "Segoe UI Emoji",
    "Segoe UI Symbol",
    "Noto Color Emoji";
  color: #444;
}
h1,
h2,
h3 {
  line-height: 1.2;
}
@media (prefers-color-scheme: dark) {
  body {
    color: #c9d1d9;
    background: #0d1117;
  }
  a:link {
    color: #58a6ff;
  }
  a:visited {
    color: #8e96f0;
  }
}