block-top and block-bottom not possible to add css

Hi,

I changed the block.tpl.php so that individial block-top/bottom can be hidden or changed:

<div id="<?php print $block_html_id; ?>">
<div class="block-top"></div>
<div class="<?php print $classes; ?>"<?php print $attributes; ?>>
  
  <?php print render($title_prefix); ?>
  <?php if ($block->subject): ?>
  <h2<?php print $title_attributes; ?>><?php print $block->subject ?></h2>
  <?php endif;?>
  <?php print render($title_suffix); ?>

  <div class="content"<?php print $content_attributes; ?>>
    <?php print $content ?>
  </div>
</div>
<div class="block-bottom"></div>
</div>