Any idea how to achieve the layout indicated in the image below with pure CSS, if the order of the divs in the markup must be as follows?
NOTE – The height of each panel is unknown; wrapper divs may be added to the markup
<body>
<div id="content"></div>
<div id="nav"></div>
<div id="search-results"></div>
</body>

This technique is taken from the question
Make a div display under another using CSS in a totally fluid layout.
It uses CSS table presentation using properties of display: table family to rearrange the presentation order of dom elements.
As said in the above question:
HTML
CSS
Demo