.chattong
{
    right: 0px;
    position: fixed;
    bottom: 0;
    z-index: 998;
    font-size: 0;
}
@media only screen and (max-width: 768px){
    .chattong img {
        margin-bottom: 70px;
        margin-right: 35px;
       
        width: 100px;
        height: 60px;
    }
}
@media only screen and (min-width: 768px){
    .chattong img {
        margin-bottom: 70px;
        margin-right: 35px;
       
        width: 150px;
        height: 90px;
    }
}