<div class="element">
</div>

.element {
  animation: rotate 2s infinite;
  background-color:#eee;
  width: 200px;
  height: 200px;
}

@keyframes rotate {
  0% {
    transform: rotate(-45deg)
  }
  100% {
    transform: rotate(45deg)
  }
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.