body {
  max-width: 40em;
  margin: 0 auto;
  padding: 5px;
  font-family: Georgia, serif;
  font-size: 18px;
  line-height: 1.6em;
  color: black;
}

h1, h2, h3 {
  font-family: sans-serif;
  font-weight: normal;
}

@media (prefers-color-scheme: dark) {
    body, blockquote {
        background-color: #000;
        color: #ccc
    }

    a {
        color: #88f
    }

    a:visited {
        color: #aaf
    }

    .response {
        background-color: #444
    }

    h1, h1 a, h2, h2 a, h3, h3 a, header#masthead a {
        color: #080
    }
}