<div class="container t-pers-50">
  <h4>perspective: 50px</h4>
  <div class="transformed"></div>
</div>

<div class="container t-pers-200">
  <h4>perspective: 200px</h4>
  <div class="transformed"></div>
</div>

BODY {
  overflow: hidden;
  padding-top: 20px;
  text-align: center;  
  }

DIV {
  height: 150px;
  width: 150px;  
  }
.container {
  position: relative;
  display: inline-block;
  height: 180px;
  margin: 0 1em 1em;
  perspective: 50px;
  }
  .t-pers-200 {
    perspective: 200px;
    }
  .transformed {
    position: absolute;
    bottom: 0;
    background: yellowgreen;
    border-radius: 5px;
    opacity: .7;
    animation: notransform 5s infinite;
    }
  H4 {
    content: attr(data-content);
    display: block;  
    margin: 0;
    padding: 7px 0;
    text-align: center;
    font-weight: normal;
    }
H4 SPAN {
  font-weight: bold;
  color: crimson;
  }
    
.transformed {
  transform: rotate3d(0,1,1, 90deg);
  }

@keyframes notransform {
  50%{
    transform: none;
    }
}