flip flop image animation in css

http://davidwalsh.name/css-flip

HTML

<div class="flip-container" ontouchstart="this.classList.toggle('hover');">
 <div class="flipper">
  <div class="front">
   <!-- front content -->
  </div>
  <div class="back">
   <!-- back content -->
  </div>
 </div>
</div>

CSS

/* entire container, keeps perspective */
.flip-container {
 perspective: 1000;
}
 /* flip the pane when hovered */
 .flip-container:hover .flipper, .flip-container.hover .flipper {
  transform: rotateY(180deg);
 }

.flip-container, .front, .back {
 width: 320px;
 height: 480px;
}

/* flip speed goes here */
.flipper {
 transition: 0.6s;
 transform-style: preserve-3d;

 position: relative;
}

/* hide back of pane during swap */
.front, .back {
 backface-visibility: hidden;

 position: absolute;
 top: 0;
 left: 0;
}

/* front pane, placed above back */
.front {
 z-index: 2;
 /* for firefox 31 */
 transform: rotateY(0deg);
}

/* back, initially hidden pane */
.back {
 transform: rotateY(180deg);
}