@media (min-width:800px) {
    .desktop-only {
        display: block !important;
    }

    .mobile-only {
        display: none !important;
    }
}

@media (max-width: 800px) {
    .mobile-only {
        display: block !important;
    }

    .desktop-only {
        display: none !important;
    }
}