CSS Float: content AFTER the loop needs to float UP

Use relative positioning to move it away from its normal position in the page flow.

Mind helping me out a bit?
Here’s my code:

<div id="container">
  <div id="navi">listpages</div>
  <div id="logo">logo</div>

<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
  <div id="header">header image</div>
  <div id="content">
    <p><?php the_content('more »'); ?></p>
  </div>
<?php endwhile; else: ?><p>Nothing found!</p><?php endif; ?>
  <div id="side">Subpage loop</div>
<?php get_footer(); ?>
</div> <!-- container -->

The important CSS parts are

#container {width:800px; margin:0px auto; padding:10px 0 0 0;}
#navi{width:650px; height:63px; float:right;}
#logo {width:150px; height:63px; float:left;}
#header{width:800px; height:250px; float:left; overflow:hidden; margin: 25px 0 15px 0;}
#content {width:100%;float:left;}
#side {float:right; width:266px;}

I just can’t get my head around it.

What are you trying to move and where do you want it to appear?

the “side” div.

On the site
https://zukunft-flughafen.at/menschen/
you see two subpages listed. That’s a temporary solution using wp-list-pages.

What I want is for the subpages to be listed like on this page
https://zukunft-flughafen.at/
That’s the “side” div that’s hugging the top right corner.

Is that understandable?