CSS3 Box Shadow with Page Curl

#box
{
  position: relative;
  width: 60%;
  background: #ddd;
  -moz-border-radius: 4px;
  border-radius: 4px;
  padding: 2em 1.5em;
  color: rgba(0,0,0, .8);
  text-shadow: 0 1px 0 #fff;
  line-height: 1.5;
  margin: 60px auto;
}

#box:before, #box:after
{
  z-index: -1;
  position: absolute;
  content: "";
  bottom: 15px;
  left: 10px;
  width: 50%;
  top: 80%;
  max-width:300px;
  background: rgba(0, 0, 0, 0.7);
  -webkit-box-shadow: 0 15px 10px rgba(0,0,0, 0.7);
  -moz-box-shadow: 0 15px 10px rgba(0, 0, 0, 0.7);
  box-shadow: 0 15px 10px rgba(0, 0, 0, 0.7);
  -webkit-transform: rotate(-3deg);
  -moz-transform: rotate(-3deg);
  -o-transform: rotate(-3deg);
  -ms-transform: rotate(-3deg);
  transform: rotate(-3deg);
}

#box:after
{
  -webkit-transform: rotate(3deg);
  -moz-transform: rotate(3deg);
  -o-transform: rotate(3deg);
  -ms-transform: rotate(3deg);
  transform: rotate(3deg);
  right: 10px;
  left: auto;
}