Source code for: http://baylorrae.com/creating-a-notification-badge-with-html5-and-css3/

markup.html

<ol>
  <li>
    <a data-notifications="10" class="button" href="#">New Comments on Your Posts</a>
  </li>
  <li>
    <a class="button" href="#">Number of Post Likes :)</a>
  </li>
<ol>

style.css

/* make sure the element has position: relative */
[data-notifications] {
  position: relative;
}

/* append the notification badge after it */
[data-notifications]:after {

  /* the burger */
  content: attr(data-notifications);

  /* the fries */
  position: absolute;
  background: red;
  border-radius: 50%;
  display: inline-block;
  padding: 0.3em;
  color: #f2f2f2;
  right: -15px;
  top: -15px;   
}