body,html{padding:0;margin:0;background-color:#fff;font-size:14px;font-family: 'arial','microsoft yahei';color:#262626;letter-spacing: 0;}
*{box-sizing:border-box;margin:0;padding:0}

.yy5{width:100%;height: 450px;}

@media (max-width: 500px) {
.yy5{height:300px;}
	  		
}