html {
  color-scheme: light dark;
  background: light-dark(#eee, #222);
}

body {
  font: 16px/1.6 system-ui, sans-serif;
  max-width: 26em;
  margin: auto;
  padding: 25vh 2em 2em;
  text-align: center;
}

h1 {
  font: inherit;
  margin: 1em 0;
}