.fb-comments, .fb-comments iframe[style] {
    width: 100% !important;
}

.fb_iframe_widget, .fb_iframe_widget span, .fb_iframe_widget span 
iframe[style] {
    width: 100% !important;
}

@media (max-width: 480px) {
    iframe[src *= "facebook"]{
        max-width:360px;
    }
}