.back_to_top{
    display: none;
    width: 77px;
    height: 77px;
    position: fixed;
    bottom: 200px;
    right: 24px;
    cursor: pointer;
}
.back_to_top_img{
    width: 100%;
    height: 100%;
}

@media (max-width: 768px) {
    .back_to_top{
        width: 47px;
        height: 47px;
        bottom: 4px;
        right: 5px;
    }
}