body {
  margin: 0;
  padding: 0;
  width: 100vw;
  height: 100vh;

  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #000;
}

#canvas {
  width: 100vmin;
  height: 100vmin;
  background-color: #006;
}