#lunbo{
    width: 100%;
    height: 500px;
    overflow: hidden;
}
@media screen and (max-width:480px){
    #lunbo{
        width: 100%;
        height: 250px;
        overflow: hidden;
    }
    #lunbo img{
        width: 100%;
        height: 250px;
        overflow: hidden;
    }
    .header .hd3 {
        height: unset;
    }

}