.t123 {
    width: 1100px;
    margin: 0 auto;
}
#vk_comments {
    float: left;
    max-width: 45%;
   
}

.fb-comments.fb_iframe_widget {
    max-width: 45%;
    float: left;
    margin-right: 5%;
}

@media screen and (max-width: 1100px) {
    div#vk_comments {
        margin: 30px auto;
        max-width: 600px;
        float: none;
        clear: both;
    }
    .fb-comments.fb_iframe_widget {
    	float: none;
    	margin-right: auto;	
    }
    .fb_iframe_widget_fluid span {
        max-width: 600px;
    }
    .t123 {
        width: 100%;
    }
}