Don't use white space in your <pre>
tag
You have:
<pre>
<code class="language-cpp">
<?php echo $query->content; ?>
</code>
</pre>
Try this:
<pre><code class="language-cpp"><?php echo $query->content; ?></code></pre>
Or:
<pre><code class="language-cpp">
<?php echo $query->content; ?>
</code></pre>