<div class="loader">
  <div class="dot"></div>
  <div class="dot"></div>
  <div class="dot"></div>
</div>

/**
 * Document defaults (don't copy these).
 */
body {
  text-align: center;
  background-color: #eee;
}

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


/* The loader container */
.loader {
  position: absolute;
  top: 50%;
  left: 50%;
  
  width: 200px;
  height: 200px;
  
  margin-top: -100px;
  margin-left: -100px;
}


/* The dot */
.loader > .dot {
  position: absolute;
  top: 50%;
  left: 50%;
  z-index: 10;

  width: 160px;
  height: 100px;
  
  margin-top: -50px;
  margin-left: -80px;

  border-radius: 5px;

  background-color: #1e3f57;

  transform-type: preserve-3d;

  animation: dot1 3s cubic-bezier(.55,.3,.24,.99) infinite;
}

.loader > .dot:nth-child(2) {
  z-index: 11;
  
  width: 150px;
  height: 90px;
  
  margin-top: -45px;
  margin-left: -75px;
  
  border-radius: 3px;
  
  background-color: #3c617d;
  
  animation-name: dot2;
}

.loader > .dot:nth-child(3) {
  z-index: 12;
  
  width: 40px;
  height: 20px;
  
  margin-top: 50px;
  margin-left: -20px;
  
  border-radius: 0 0 5px 5px;
  
  background-color: #6bb2cd;
  
  animation-name: dot3;
}

@keyframes dot1 {
  3%, 97% {
    width: 160px;
    height: 100px;

    margin-top: -50px;
    margin-left: -80px;
  }
  30%, 36% {
    width: 80px;
    height: 120px;

    margin-top: -60px;
    margin-left: -40px;
  }
  63%, 69% {
    width: 40px;
    height: 80px;

    margin-top: -40px;
    margin-left: -20px;
  }
}

@keyframes dot2 {
  3%, 97% {
    width: 150px;
    height: 90px;

    margin-top: -45px;
    margin-left: -75px;
  }
  30%, 36% {
    width: 70px;
    height: 96px;

    margin-top: -48px;
    margin-left: -35px;
  }
  63%, 69% {
    width: 32px;
    height: 60px;

    margin-top: -30px;
    margin-left: -16px;
  }
}

@keyframes dot3 {
  3%, 97% {
    width: 40px;
    height: 20px;

    margin-top: 50px;
    margin-left: -20px;
  }
  30%, 36% {
    width: 8px;
    height: 8px;

    margin-top: 49px;
    margin-left: -5px;
    
    border-radius: 8px;
  }
  63%, 69% {
    width: 16px;
    height: 4px;

    margin-top: -37px;
    margin-left: -8px;
    
    border-radius: 10px;
  }
}