<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			*{
				margin: 0;
				padding: 0;
			}
			#cont{
				position: absolute;
				margin-left: 40%;
				margin-top: 40px;
			}
			#cont p:nth-of-type(1){
				width: 20px;
				height: 30px;
				background: gray;
				position: absolute;
				left:0;
				top:50%;
				font-size: 14px;
				line-height: 30px;
				text-align: center;
				display: none;
			}
			#cont p:nth-of-type(2){
				width: 20px;
				height: 30px;
				background: gray;
				position: absolute;
				right:0;
				top:50%;
				font-size: 14px;
				line-height: 30px;
				text-align: center;
				display: none;
			}
		</style>
	</head>