SOURCE

<div class="stamp">
  <div class="ssa">嘿嘿</div>
</div>

.stamp {  
  position: relative;
  left: 100px;
  top:100px;
  width: 290px;
  height: 90px;
  display: inline-block;
  padding: 15px;
  background: radial-gradient( transparent 1px, transparent 4px, white 4px, white );
  background-size: 20px 20px;
  background-position: -10px 0;  
}
 .stamp:after {
  content: '';
  position: absolute;
  left: 5px;
  top: 5px;
  right: 5px;
  bottom: 5px;
  box-shadow: 0 0 20px 1px rgba(0, 0, 0, 0.1);
  z-index: -1;
  background-color:#fff;
} 
.ssa{  
  box-sizing:border-box;
  width：100%;
  height:100%;
  padding:5px;
  background-color:#ddd;
  border-radius:3px;
}