main.css

body {
  background-color: #eee;
  font-family: palatino, serif;
}

* {
  transition: all ease 1s;
}

.game {
  position: absolute;
  top: 20px;
  left: calc(50% - 320px);
  width: 640px;
  height: 480px;
  box-shadow: 3px 3px 20px #000;
}

#inf {
  font-size: 20px;
  background-color: rgba(255,255,255,0.8);
  line-height: 24px;
  border-top: 1px solid #000;
  position: absolute;
  bottom: 0;
  width: 100%;
  padding: 10px;
  text-align: center;
  box-sizing: border-box;
}

#mdl {
  font-size: 50px;
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  background-color: #eee;
  line-height: 480px;
  text-align: center;
}

canvas {
  width: 640px;
  position: absolute;
  top: 0;

  image-rendering: -webkit-optimize-contrast;
  image-rendering: -moz-crisp-edges;
  image-rendering: pixelated;
}