body {
  background: #2b2b2b;
  height: 100vh;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-family: Helvetica neue, roboto;
  overflow:hidden;
}

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

/*
canvas {
  position: absolute; 
  left: 0; 
  top: 0;
}
*/

button:hover {
	background-color: #000;
	color: #fff;
}