body {
  background-color: lightblue;
  /* leave it to hide the scrollbars */
  overflow: hidden;
  margin:0 auto;
  padding:0;
}
canvas{
  padding: 0;
  margin: auto;
  display: block;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}