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

html {
  display: table;
  margin: auto;
}

body {
  background-color: #202020;
  display: table-cell;
  vertical-align: middle;
  color: #f9f9f9;
}

canvas {
  background-color: #202020;
  display: block;
}