<style>
  .blue {
      z-index: 3;
      position: relative;
      background-color: #8EC4D0;
      margin-bottom: 15px;
      width: 120px;
      height: 120px;
      color: #FFF;
  }
  .red {
      z-index: 2;
      position: relative;
      background-color: #FF4D4D;
      width: 120px;
      height: 120px;
      color: #FFF;
      margin-top: -50px;
      margin-left: 50px;
  }
</style>

<div class="blue">Blue</div>
<div class="red">Red</div>