Corner Up Shadow Technique - CSS

contnt.html

<div class="effect3" style="margin:20px;">
    <img class="effect3" src="http://0777.ir/img/lndl.png"         
    original-src="http://pearlsquirrel.com/profilethumbnails/$thumbnail" 
    width="180" height="180" alt="PearlSquirrel"/>
</div>

corner-shadow.css

.effect3
{
  position: relative;
}
.effect3:before
{
  z-index: -1;
  position: absolute;
  content: "";
  bottom: 15px;
  left: 10px;
  width: 50%;
  top: 80%;
  max-width:155px;
  max-height:18px;
  background: #777;
  -webkit-box-shadow: 0 15px 10px #777;
  -moz-box-shadow: 0 15px 10px #777;
  box-shadow: 0 15px 10px #777;
  -webkit-transform: rotate(-4deg);
  -moz-transform: rotate(-4deg);
  -o-transform: rotate(-4deg);
  -ms-transform: rotate(-4deg);
  transform: rotate(-4deg);
}