#overflow{
	width: 450px;
	height: 70px;
	margin: 0 auto;
	margin-bottom: 30px;

}
#overflow p{
	text-align: center;
	font: 20px/70px "微软雅黑";
	font-weight: bold;
	color:#000;
}
canvas{
	margin: 50px auto;
	display: block;
	box-shadow: -2px -2px 2px #E9E9E9, 5px 5px 5px #cccccc;
}