@media only screen and (max-width: 550px) {
    .show_mob {
        display: block;
    }
    .show_desk {
        display: none;
    }
    .auth_images {
        margin-bottom: 20px;
    }
}
@media only screen and (min-width: 550px) {
    .show_mob {
        display: none;
    }
    .show_desk {
        display: block;
    }
}