; data-side=&quot;collapse&quot;&gt;
    &lt;i class=&quot;fa fa-caret-left&quot;&gt;&lt;/i&gt;
    (not required, expand/collapse for app-side)
  &lt;/div&gt;
  &lt;div class=&quot;app-main&quot;&gt;
    ... (required, must be single)
  &lt;/div&gt;
&lt;/div&gt;
</code></pre>
                    </div>
                    <div class="d-flex flex-row m-l-30 flex-fill astro-3HS6YOU4">
                      <div class="bg-secondary h3 p-3 astro-3HS6YOU4">
                        .app-side
                    