.back_btn {
    width:80px;
    height:30px;
    background-color:#3c8dbc;
    border:none;
    border-radius:6px;
    float:right;
}
.back_btn span{
    font-size:16px;
    text-align:center;
    color:#fff;
    text-decoration:none;
    display:block;
    line-height:20px;
}