BuddyPress.org

Roger, I placed this in the styles.css file.

ul#topic-post-list li:first-child {
padding: 4px;
background: #FCEC8F;
border: 1px solid #ddd;
-moz-border-radius: 6px;
-webkit-border-radius: 6px;
-moz-box-shadow: 2px 2px 2px #dddddd;
-webkit-box-shadow: 2px 2px 2px #dddddd;
}

I then removed my div tags that were working in the topic.php (restoring original) … and the first post failed to load with a different css.

Update
OK! I found my mistake Roger. This works – except the whole post with the avatar is surrounded and I just wanted the post content.