Pure CSS Tooltips

HTML

<!-- normally this stuff would be on the html element -->
<!--[if lt IE 7]>  <div class="ie ie6 lte9 lte8 lte7"> <![endif]-->
<!--[if IE 7]>     <div class="ie ie7 lte9 lte8 lte7"> <![endif]-->
<!--[if IE 8]>     <div class="ie ie8 lte9 lte8"> <![endif]-->
<!--[if IE 9]>     <div class="ie ie9 lte9"> <![endif]-->
<!--[if gt IE 9]>  <div> <![endif]-->
<!--[if !IE]><!--> <div>             <!--<![endif]-->
  <div class="wrapper" data-tooltip="I am a tooltip!">
    I have a tooltip.
  </div>
</div>

CSS

.wrapper {
  
  
}

.wrapper:after {
  content: attr(data-tooltip);
  background: #1496bb;
  bottom: 100%;
  color: #fff;
  display: block;
  left: -25px;
  margin-bottom: 15px;
  opacity: 0;
  padding: 20px;
  pointer-events: none;
  position: absolute;
  z-index: 1;
  width: 100%;
  -webkit-transform: translateY(10px);
     -moz-transform: translateY(10px);
      -ms-transform: translateY(10px);
       -o-transform: translateY(10px);
          transform: translateY(10px);
  -webkit-transition: all .25s ease-out;
     -moz-transition: all .25s ease-out;
      -ms-transition: all .25s ease-out;
       -o-transition: all .25s ease-out;
          transition: all .25s ease-out;
  -webkit-box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
     -moz-box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
      -ms-box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
       -o-box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
          box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
}

/* CSS Triangles - see Trevor's post */
.wrapper:before {
  border-left: solid transparent 10px;
  border-right: solid transparent 10px;
  border-top: solid #1496bb 10px;
  top: -15px;
  content: " ";
  height: 0;
  left: 50%;
  margin-left: -13px;
  position: absolute;
  z-index: 2;
  width: 0;
  opacity: 0;
  -webkit-transform: translateY(10px);
     -moz-transform: translateY(10px);
      -ms-transform: translateY(10px);
       -o-transform: translateY(10px);
          transform: translateY(10px);
  -webkit-transition: all .25s ease-out;
     -moz-transition: all .25s ease-out;
      -ms-transition: all .25s ease-out;
       -o-transition: all .25s ease-out;
          transition: all .25s ease-out;
}
  
.wrapper:hover:after , .wrapper:hover:before {
  opacity: 1;
  pointer-events: auto;
  -webkit-transform: translateY(0px);
     -moz-transform: translateY(0px);
      -ms-transform: translateY(0px);
       -o-transform: translateY(0px);
          transform: translateY(0px);
}

/* IE can just show/hide with no...