title: How might I customize the display of an auto-complete pop-up 'window'?
body: <p>I'm trying to get auto-complete pop-up windows <em>just right</em> within emacs, and I'm pretty close to something I like:</p>
  
  <p><img src="https://i.stack.imgur.com/OVPMX.png" alt="Emacs pop-up"></p>
  
  <p>but in a perfect world, I would be able to customize the border, margin, and padding of the help box generated. I've scoured the documentation, tried playing around with pos-tip, but just can't get this right.</p>
  
  <p>Any suggestions on how I can get a bit more customization out of the display of my auto-complete pop-ups?</p>