.biaodan{	max-width: 100%; 
	padding: 0px;
	box-sizing: content-box;
	-moz-box-sizing: content-box;
	margin: 0;margin:auto;
	margin: 0 auto;
	padding: 0;
	background-attachment: fixed;
	background-position: 50% 50%;
	background-size: cover;
}


@media screen and (max-width: 600px) {
	
}