title: Full width css dropdown menu
body: <p>I am trying to create pure and simple CSS drop down menu which will open in a full width mode underneath each item but will also keep each drop down menu underneath it's parent item.
  this image better explains what I am trying to achieve:</p>
  
  <p><img src="https://i.stack.imgur.com/T12F4.png" alt="enter image description here"></p>
  
  <p>I just can't figure out how to keep the nested UL inside each li but also have a full width background wrapping it all.</p>
  
  <p>Here is a demo I prepared on <strong>Codepan</strong>:
  <a href="http://cdpn.io/wLjFm" rel="noreferrer">http://cdpn.io/wLjFm</a></p>