html {
  background-color: #181818;
}

html, body {
  margin: 0;
  padding: 0;
  height:100%;
}

body {
  display: flex;
  /* centers canvas horizontally. */
  justify-content: center;
  /* centers canvas vertically. */
  align-items: center;
}

canvas {
  /* no scrollbars */
  display: block;
  image-rendering: -webkit-optimize-contrast;
}