title: Bootstrap list-group-items flush with list-group container
body: <p>This is nitpicky; I'm working in Bootstrap with a fixed-sized list-group. When it starts, it has a nice outline/bottom border, but when I scroll the list, I lose it. I've tried breaking the top list-group-item from the rest of the group using a <code>&lt;p&gt;</code>, but I'm not satisfied with how that looks either.</p>
  
  <p><img src="https://i.stack.imgur.com/qbvYG.png" alt="The nice-looking space between list-group and list-group-item">
  Above: The nice-looking space between list-group and list-group-item</p>
  
  <p><img src="https://i.stack.imgur.com/nRMvJ.png" alt="When the two elements are flush, the bottom outline of the list-group-item above goes away">
  When the two elements are flush, the bottom outline of the list-group-item above goes away</p>