html,
body {
  height: 100%;
  padding: 0;
  margin: 0;
  background-color: black;
}

#container {
  width: auto;
  height: 100%;
  overflow: hidden;
  position: relative;
}
#overlay,
#viewport {
  image-rendering: pixelated;
  position: absolute;
  top: 0;
  left: 0;
}