:root {
  background: #0f0;
}

:root.is-transparent {
  background: transparent;
}

body {
  margin: 0;
  padding: 0;
}

#scene {
  background: #000;
  color: white;
  width: 1920px;
  height: 1080px;
  overflow: hidden;
  contain: strict;
}

:root.is-transparent #scene {
  background: transparent;
}