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

main {
  text-align: center;
  width: 100%;
}

canvas {
  display: block;
  margin: auto;
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}