Modal Wrapper shows Header and Footer

I successfully opened internal posts on modal, but the wrapper is displaying the whole page header and footer as well as the content, how do I avoid showing up the header and footer? I’ve already tried modifying the CSS but got no solution. I use the class “modal-link” and call the_permakink() php:

<div class=”modal-link”>“><?php the_post_thumbnail( ‘full’, array( ‘class’ => ‘img-responsive center-block’ ) ); ?></div>

The page loads well, but it calls the header and footer.