html,
body {
  height: 100%;
}
body {
  background: #000;
  background: radial-gradient(#333, #000);
  overflow: hidden;
}
.scene {
  background: #000;
  bottom: 0;
  box-shadow:
    0 0 0 7px #222,
    0 80px 100px 20px #000;
  height: 100vmin;
  left: 0;
  max-height: 95%;
  max-width: 100%;
  margin: auto;
  position: absolute;
  right: 0;
  top: 0;
  width: 100vmin;
}
canvas {
  height: 100%;
  left: 0;
  position: absolute;
  top: 0;
  width: 100%;
}