title: how to style jquery sortable target list before drop
body: <p>Using jquery sortable i can style a placeholder inside a conect list defined in <code>connectWith</code> option, so i can see where content will be dropped.
  However i can't find a way to style the list which contains the placeholder.</p>
  
  <p>My code:</p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;div class="sortable"&gt;
      &lt;div class="item"&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="sortable"&gt;&lt;/div&gt;
  &lt;div class="sortable"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>Javascript:</p>
  
  <pre><code>$(".sortable").sortable({
      connectWith: ".sortable",
      over: function(event,ui){
          //add class .hover to list
      },
      change: function(event, ui) {
          //style placeholder
          ui.placeholder.css({
              visibility: 'visible',
              background: '#EEE'
          });
      }
  });
  </code></pre>
  
  <p><a href="https://jsfiddle.net/quakeglen/km0sw55t/" rel="nofollow">Demo here</a></p>