style.css

html, body {
  background-color: #202020;
  margin: 0;
  padding: 0;
  border-spacing: 0;
  position: relative;
  width: 100%;
  height: 100%;
}

#gameCanvas {
  position: absolute;
  display: block;
  margin: auto;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  box-sizing: border-box;
  image-rendering: -moz-crisp-edges;
  image-rendering: -webkit-crisp-edges;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

#gameCanvas:hover {
  cursor: none;
}

#gameCanvas:focus {
  outline:0;
}

@media only screen and (min-width: 960px) and (min-height: 600px) {
  #gameCanvas {
    width: 960px;
    height: 600px;
  }
}

@media only screen and (min-width: 1440px) and (min-height: 900px) {
  #gameCanvas {
    width: 1440px;
    height: 900px;
  }
}