body {
  background-color: black;
  margin: 0;
  padding: 0;
  display: flex;

  /* This centers our sketch horizontally. */
  justify-content: center;

  /* This centers our sketch vertically. */
  align-items: center;
}
canvas {
  width: 100%;
  height: 100%;
  display: block;
}

* { margin:0; padding:0; } /* to remove the top and left whitespace */

html, body { width:100%; height:100%; } /* just to be sure these are full screen*/