A CodePen by Jeffd. 3D Rotating Cube - based on this tutorial http://davidwalsh.name/css-cube?utm_source=html5weekly&utm_medium=email

index.html

<div class="wrap">
  <div class="cube">
    <div class="front">front</div>
    <div class="back">back</div>
    <div class="top">top</div>
    <div class="bottom">bottom</div>
    <div class="left">left</div>
    <div class="right">right</div>
  </div>
</div>

style.css

body {
  margin: 0;
  width: 100%;
  /*border: 1px solid orange;*/
}

.wrap {
  margin: 0 100px;
	perspective: 800px;
	perspective-origin: 50% 100px;
  /*border: 1px solid red;*/
  width: 100%;
  height: 300px;
  margin: 0;
  margin-top: 50px;
}

.cube {
	position: relative;
  margin: 0 auto;
	width: 200px;
	transform-style: preserve-3d;
  animation: spin 4s infinite linear;
  /*border: 1px solid blue;*/
}

.cube div {
	position: absolute;
	width: 200px;
	height: 200px;
  background-color: rgba(42,222,38,0.25);
  /*border: 1px solid green;*/
  box-shadow: inset 4px 4px 30px rgba(0,0,0,0.25);
  text-align: center;
  font-family: sans-serif;
  line-height: 200px;
  transition: background-color 1s ease;
}

.cube div:hover {
  background-color: rgba(255,0,38,0.25);
}

.back {
	transform: translateZ(-100px) rotateY(180deg);
}

.right {
	transform: rotateY(-270deg) translateX(100px);
	transform-origin: top right;
}

.left {
	transform: rotateY(270deg) translateX(-100px);
	transform-origin: center left;
}

.top {
	transform: rotateX(-90deg) translateY(-100px);
	transform-origin: top center;
}

.bottom {
	transform: rotateX(90deg) translateY(100px);
	transform-origin: bottom center;
}

.front {
	transform: translateZ(100px);
}

@keyframes spin {
  from { transform: rotateY(0) }
  to { transform: rotateY(360deg) }
}