* {
  padding: 0;
  margin: 0;
}

canvas:first-child {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: inline-block;
  margin: 0 auto;
}
canvas:nth-child(2) {
  background: #64B5F6;
  display: block;
  margin: 0 auto;
}