JSFiddle - React, Tailwind, and code Playground

HTML

<div id="body">

   <header class="">

      <nav>

            content<span>content</span>
            <div>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            content<span>content</span>
            </div>
      </nav>

   </header>

</div>

CSS

/*obligatory css*/

        #body {position:relative;} 

            header { min-width:900px; background-color:#000000; border-bottom:1px #333333 solid; height:auto; }

        nav { color:#ffffff; position:absolute; width:100%;}
        nav span { color:#000000; }

JavaScript

$('header').css('height', $('nav').height());
$('nav div').dblclick(function(){$(this).remove();});
$('header').click(function(){$(this).css('height', $('nav').height());});