body {
  margin: 0;
  background: black;
}

shader-doodle {
  display: block;
  width: 100vw;
  height: 100vh;
  position: fixed;
  top: 50%;
  left: 50%;
  -webkit-transform: translate3d(-50%, -50%, 0);
          transform: translate3d(-50%, -50%, 0);
}