style.css

* { 
  padding:0; 
  margin: 0;
}

html,body{
  height: 100%;
  width:100%;
}

canvas {
  display: block;
}

body{
  color: #fff;
  font-family: Verdana,Arial, sans-serif;
  font-size: 18px;
}
h1{
	font-size: 30px;
}

a{
	color: #fff;
	text-decoration:none;
}
a:hover{
	text-decoration: underline;
}
.button{
  background: #185da8;
  border-radius: 5px;
  display: block;
  font-size: 18px;
  margin-top: 20px;
  border: none;
  padding: 10px;
  width: 120px;
  color: #fff;
}
.button:hover{
	background: #2488f5;
	color: #fff;
	text-decoration: none;
  cursor: pointer;
}
#game{
  width: 700px;
  height: 600px;
  position: relative;
  left: 50%;
  top: 40px;
  margin: 0 0 0 -350px;
  background: linear-gradient(-180deg, #040024 0%, #07165C 97%);
  /*to top：设置渐变从下到上。相当于: 0deg
    to right: 设置渐变从左到右。相当于: 90deg
    to bottom：设置渐变从上到下。相当于: 180deg。或者-180*/
}

.game-panel {
	width: 700px;
	height: 600px;
	position: absolute;/* 将UI置于画布之上 */
}
.game-ui{
  display: none;
  padding: 55px;
  box-sizing: border-box;/* 宽和高包括了padding和border的宽度 */
	height: 100%;
}
.game-level {
  margin-top: 10px;
  font-size: 18px;
}
.game-desc {
  font-size: 14px;
  margin-top: 10px;
  width: 330px;
}
[data-status="start"] .game-intro {
  display: block;
  padding-top: 180px;
  background: url(./img/bg.png) no-repeat 430px 180px;
  background-size: 200px;
}

[data-status="playing"] .game-info {
  display: block;
  position: absolute;
  top:0;
  left:0;
  padding:20px;
}

[data-status="failed"] .game-failed, 
[data-status="success"] .game-success,
[data-status="all-success"] .game-all-success,
[data-status="stop"] .game-stop{
  display: block;
  padding-top: 180px;
  background: url(./img/bg-end.png) no-repeat 380px 190px;
  background-size: 250px;
}