:root {
  color-scheme: light dark;
  background: light-dark(rgb(255 255 255), rgb(24 24 24));
}

html,
body {
  margin: 0;
}

body {
  box-sizing: border-box;
  padding: 1rem;
  background: inherit;
}

iframe {
  display: block;
  width: 100%;
  height: calc(100vh - 2rem);
  margin: 0 auto;
  border: 0;
}