So, I've tried a few things to get a border bottom after each wordpress post on my feedback, but I can't quite get it.

http://www.connect4webdesign.com/ournewsblog/

I tried a to target one post specifically and then I tried to target all posts. My goal of course is on class for all posts, but I wanted to test it on one of the posts.

.post-277 {
border-bottom:thin solid #333;
background-color:#66FF33;

}

.onepost {
border-bottom:thin solid #333;
background-color:#66FF33;

}



<?php
$args = array( 'posts_per_page' => 100, 'order'=> 'ASC', 'orderby' => 'title' );
$postslist = get_posts( $args );
foreach ( $postslist as $post ) :
setup_postdata( $post ); ?>



<section class="onepost">


<section <?php post_class()?>>

<section class="PostsDates">
<p class="PostsDate"><?php the_time(get_option('date_format'));?></p>
</section>


<section class="DateAndExcerpt">

<p class="PostsTitle"><?php the_title(); ?> </p>

<section class="PostsExcerpt"><?php the_excerpt(); ?></section>

</section> <!--DateAndExcerpt-->


</section> <!--post_class-->

</section> <!--onepost-->



<?php
endforeach;
wp_reset_postdata();
?>