@import url(http://fonts.lug.ustc.edu.cn/css?family=Fjalla+One);

canvas {
  position: absolute;
  z-index: 1;
  top: 0;
  left: 0;
}

div {
  font-family: 'Fjalla One', sans-serif;
  position: absolute;
  z-index: 10;
  width: 100%;
  text-align: center;
  font-size: 18px;
  top: 15px;
  left: 0;
}