body {
  background-color: rgb(0, 0, 0);
  overflow: hidden;
  display: flex;
  margin: 0;
  justify-content: center;
  align-items: center;

}
* { 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*/