_the_post_thumbnail as DIV background?

Is there a simple way to put my queried post_thumbnail_image into a div background, to force square crop? Here’s the code:

<div id="featuretitle"><h1>Furniture</h1></div>
<?php
$cat_id = 6;
$latest_cat_post = new WP_Query( array('posts_per_page' => 1, 'category__in' => array($cat_id)));
if( $latest_cat_post->have_posts() ) : while( $latest_cat_post->have_posts() ) : $latest_cat_post->the_post();
the_post_thumbnail();
the_content();
 ?>
<a href="https://summerhousefurnishings.farmroaddesign.com/?page_id=32"><div id="featurelink">View All Furniture</div></a>
<?php endwhile; endif; ?>