.rounded:before {
  background: transparent url(top-right.png) scroll no-repeat top right;
  margin-bottom: -20px;
  height: 30px;
  display: block;
  border: none;
  content: url(top-left.png);
  padding: 0;
  line-height: 0.1;
  font-size: 1px;
}

.rounded:after {
  display: block;
  line-height: 0.1;
  font-size: 1px;
  content:  url(bottom-left.png);
  margin: 0 0 -1px 0;
  height: 30px;
  background: white;
  background: transparent url(bottom-right.png) scroll no-repeat bottom right ;
  padding: 0;
}