html,
body {
  display: flex;
  align-items: stretch;
  align-content: stretch;
  width: 100%;
  height: 100%;
  margin:0;
  padding:0;
  background: #35556E;
}

#canvas {
  display: block;
  width: 100%;
  height: 100%;
  margin: 0 auto;
}