/* author: https://codepen.io/fleemaja/pen/BMbrqN */
html, body {
    font-family: sans-serif;
    margin: 0;
    padding: 0;
    overflow: hidden;
  }
  
  canvas {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    margin: auto;
  }