#mobile {
    display: none;
}

#desktop {
    display: block;
}

@media (min-width: 600px) and (max-width: 991px) {
    #mobile {
        width: 62%;
        margin: 20px auto 0;
    }
}

@media only screen and (max-width: 991px) {
    #mobile {
        display: block;
    }
    #desktop {
        display: none;
    }
}