我在WordPress中显示相关帖子，没有任何插件，问题是我想通过CSS在相关帖子中显示自定义大小的图像，如何做到这一点？

这是我的相关邮编。

<?php endwhile; endif; ?>
<?php $orig_post = $post;
global $post;
$categories = get_the_category($post->ID);
if ($categories) {
$category_ids = array();
foreach($categories as $individual_category) $category_ids[] = $individual_category->term_id;
$args=array(
\'category__in\' => $category_ids,
\'post__not_in\' => array($post->ID),
\'posts_per_page\'=> 8, // Number of related posts that will be shown.
\'caller_get_posts\'=>1
);
$my_query = new wp_query( $args );
if( $my_query->have_posts() ) {
echo \'<div id="related_posts"><h3>Related Posts</h3><ul>\';
while( $my_query->have_posts() ) {
$my_query->the_post();?>
<li><div class="relatedthumb"><a href="<? the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>"><?php the_post_thumbnail(); ?></a></div>
<div class="relatedcontent">
<h3><a href="<? the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>"><?php the_title(); ?></a></h3>
<p>Last updated: <?php the_modified_date(); ?></p>
</div>
</li>
<?
}
echo \'</ul></div>\';
}
}
$post = $orig_post;
wp_reset_query(); ?>