html, body {
  margin: 0px;
  padding: 0px;
  background-color: #333;
  color: white;
}
#canvas {
  width: 100%;
  height: 100%;
}
#debug {
  position: absolute;
  left: 0px;
  top: 0px;
  margin: 10px;
  padding: 10px;
  background-color: rgba(0, 0, 0, .5);
  border: 1px solid white;
  border-radius: 10px;
}