Using :after to clear floating elements

Write like this:

.wrapper:after {
    content: '';
    display: block;
    clear: both;
}

Check this http://jsfiddle.net/EyNnk/1/

No, you don't it's enough to do something like this:

<ul class="clearfix">
  <li>one</li>
  <li>two></li>
</ul>

And the following CSS:

ul li {float: left;}


.clearfix:after {
  content: ".";
  display: block;
  clear: both;
  visibility: hidden;
  line-height: 0;
  height: 0;
}

.clearfix {
  display: inline-block;
}

html[xmlns] .clearfix {
   display: block;
}

* html .clearfix {
   height: 1%;
}