body {
  color: #000;
  background-color: #ffffea;
  font-size: 14pt;
  line-height: 1.5rem;
  max-width: 640px;
  margin: 0 auto;
}
main {
  max-width: 720px;
}

.ascii-art {
  white-space: pre;
  display: inline-block;
  font-family: monospace;
  font-size: 14px;
  line-height: 1.1rem;
}

.sourceCode {
  overflow-y: hidden;
}
pre.sourceCode {
  border: 1px solid #333;
  font-size: 12pt;
  background: #ddd;
  padding: 4px;
  color: #111;
}
 @media (prefers-color-scheme: dark) {
   body {
     background-color: #333;
     color: #eee;
   }
   a {
     color: #eea;
   }
}