1. <div class="fb-comments"data-href="http://yourdomain.tld" data-num-posts="2" mobile="false"></div>
  2. <style>.fb-comments, .fb-comments iframe[style], .fb-like-box, .fb-like-box iframe[style] {width: 100% !important;}
  3. .fb-comments span, .fb-comments iframe span[style], .fb-like-box span, .fb-like-box iframe span[style] {width: 100% !important;}
  4. </style>