* {
  -webkit-box-sizing: border-box;
     -moz-box-sizing: border-box;
          box-sizing: border-box;
}

body { font-family: sans-serif; }

.masonry {
  background: #EEE;
  max-width: 100%;
  position: relative;
}
.grid-sizer{
  width: 25%;
  
}

.item {
  width:  25%;
  
  float: left;
  background: #D26;
  border: 2px solid #333;
  border-color: hsla(0, 0%, 0%, 0.5);
  border-radius: 5px;
}



/* position stamp elements with CSS */
.stamp {
  position: absolute;
  background: orange;
  border: 4px dotted black;
  left: 25%;
  top: 10px;
  width: 50%;
  height: 500px;
}