@media only screen and (max-width:1040px){
    @media only screen and (min-width:551px) {
        .index_header{
            min-height: 150px;
        }
        .logo_div{
            width: 200px;
            height: 95%;
        }
        .sign_btn{
           margin-top: 12%;
        }
       
        .item_div{
            width: 30%;
            margin:3px 0px 3px 2%;
            height: 140px;
         
        }
        .img_area{
            padding: 0px;
            height: 90%;
            max-width: 90%;
            margin-left: 4%;    
        }
       .txt_div{
            margin:0px 0px 4px 10%;
        }
/**/
}
}