anchor.diff:  
   <div class="col-xs-4 col-sm-3 col-md-3 droppable" data-num="x">
     <p>Pinky</p>
  +</div>
  +<div class="col-xs-4 col-sm-3 col-md-3 draggable" data-num="y">
  +  <p>Hula hoops</p>
   </div>
   
   <div class="col-xs-4 col-sm-3 col-md-3 draggable" data-num="disc">
  
positive.code: <body>
  <div class="container">
  <h1>How well do you know Lisa and Dave?</h1>
  <h3>drag the <span style="color:#afdcff;">blue</span> cards to the <span style="color:#f69c9d;">pink</span> cards to make a match.</h2>
  <div class="col-xs-4 col-sm-3 col-md-3 draggable" data-num="lisa-gen">
    <p>Lisa</p>
  </div>
  
negative.code: </div>
  
  <div class="col-xs-4 col-sm-3 col-md-3 draggable" data-num="a">
    <p>Tuna</p>
  </div>
  <div class="col-xs-4 col-sm-3 col-md-3 droppable" data-num="david-berry">
    <p>This is Dave's favorite berry.</p>
  