.fb.fb-button button {
    /**
        width: 100%;
        margin-left: 0px !important;
    **/
    /**margin-top: 1em;**/
}

@media (max-width: 576px) {
    .fb.fb-button button {
        /**
            width: 100%;
            margin-left: 0px !important;
        **/
        margin-top: 1em;
    }
}