html,
body {
  font-family: 'Helvetica Neue', Arial, sans-serif;
  -webkit-text-size-adjust: none;
  color: #333;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}
#canvas-demo {
  background-color: #F4F4F4;
}
code-game {
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  width: 800px;
  height: 500px;
  margin: auto;
  border: 1px solid #CCC;
  padding: 0;
}