anchor.diff:  
   @media only screen and (max-width: 400px) {
     .tile {
  -   width: 45%;
  - }
  -}
  +   max-width: 100%;
  + }
  +} %>
   
   .citation {
     color: #4C4C4C;
  
positive.code:   margin: 0 auto;
    overflow: auto;
    padding: 10px 0;
  }
  
  .tile {
  
negative.code:   height: 130px;
  }
  
  <%# @media only screen and (max-width: 800px) {
   .tile {
     width: 30%;
   }
  