html,
body {
  margin: 0;
  height: 100%;
  width: 100%;
  background: transparent;
}

body {
  display: flex;
  flex-direction: column;
  font: 13px system-ui, sans-serif;
}

iframe {
  flex-grow: 1;
  width: 100%;
  height: 100%;
  border: 0;
  background: transparent;
  color-scheme: inherit;
}