原生js随机点名

 * {
	padding:0;
	margin:0;
}
.content-bg {
	width:1365px;
	background:url(http://www.jq22.com/img/cs/500x300-1.png) no-repeat;
	background-size:cover;
	height:650px;
	background-clip:content-box;
}
.content {
	position:absolute;
	left:0;
	right:0;
	top:0;
	bottom:0;
	width:100%;
	height:650px;
	text-align:center;
	margin:0 auto;
	background:rgba(255,255,255,0.3);
}
ul {
	list-style:none;
	width:620px;
	margin:0 auto;
	overflow:hidden;
}
li {
	float:left;
	width:100px;
	border-radius:10px;
	background-size:cover;
	background-position:center;
	background-repeat:no-repeat;
	text-align:center;
	line-height:50px;
	background-color:skyblue;
	border:1px solid #333333;
	margin:10px;
	font-weight:bold;
}
button {
	display:block;
	border-radius:10px;
	width:80px;
	height:50px;
	margin:0 auto;
	background:transparent;
	color:skyblue;
	border:none;
	font-size:22px;
	color:red;
}
button:hover {
	cursor:pointer;
}
.active {
	background-color:slateblue;
}
.active2 {
	background-color:red;
}
.text {
	position:absolute;
	left:100px;
	top:50px;
	text-align:left;
	font-weight:bold;
	line-height:30px;
}
h1 {
	margin-bottom:50px;
}