A CodePen by Stacey Reiman. FORK of flip card, this was not my own creation. Here are the author's comments (url at bottom): Flip Card - My goal was to create re-useable card-like elements that flip on hover (or tap!) I've built markup for a flippable card that you can use to hold any content you want on the front or the back of the card. Simply…

index.html

<!-- 
Wrote a blog post about how it all works:
http://andymcfee.com/2012/08/24/css3-flip-cards/
-->

<div class="viewport">
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
  <div class="flip-card">
    <div class="card-front">
      Front!
    </div>
    <div class="card-back">
      Back!
    </div>
  </div>
  
</div>

style.scss

@import "compass";
$default-transition-duration: 500ms;
$perspective: 300;

/***
* CSS3 FLIP CARDS
* Markup for an element that a user can hover to reveal content on the back, like a card
* Browser Support: Safari, Firefox, Chrome, IE8+, and Touch Devices; (IE9 and below will not have any flip effect but will just change on hover)
***/

.flip-card {
  display: block;
  position: relative;
  z-index: 1000;
  width: 100px; 
  height: 100px;
  
  .card-front,
  .card-back {
    @include backface-visibility(hidden);
    @include single-transition(transform);
    display: block;
    height: 100%;
    position: absolute;
    width: 100%; 
  }

  .card-front {
    @include transform3d(perspective($perspective) rotateY(0));
    z-index: 900;
  }

  .card-back {
    @include rotateY(-180deg); //Using rotate instead of transform prevents the back of the card from flipping on page load because transition is only targeting transform. Super sweet. 
     z-index: 800;
  }

  &:hover {
    .card-front { 
      @include transform(rotateY(180deg)); //No 3D fallback
      @include transform3d(perspective($perspective) rotateY(180deg)); 
    }
    .card-back { 
      z-index: 950; //No transform fallback
      @include transform(rotateY(0deg)); //No 3D fallback
      @include transform3d(perspective($perspective) rotateY(0deg)); 
    }
  }
}




/*** Just for show... ***/

.flip-card {
  @include text-shadow(1px 1px 0 rgba(darken(#1B8CE8, 20%), .8) );
  color: #fff;
  cursor: pointer;
  float: left;
  font-weight: bold;
  margin: 10px;
  text-align: center;
  text-transform: uppercase;
  min-width: 100px;
  max-width: 400px;
  
  .card-front,
  .card-back {
    @include border-radius(5px);
    @include box-shadow(1px 1px 2px rgba(darken(#1B8CE8, 20%), .8));
    @include box-sizing(border-box);
    border: 1px solid darken(#1B8CE8, 40%);
    padding: 40px 0;
  }

  .card-front {
    @include box-sizing(border-box);
    background-color: #499bea; // Old browsers
  	@include filter-gradient(#499bea, #207ce5, vertical);
		@include background-image(linear-gradient(top,  #499bea 0%,#207ce5 100%));

  }

  .card-back {
    @include box-shadow(0 0 20px rgba(darken(#1B8CE8, 10%), .8) inset);
		background-color: #478ce0; // Old browsers
		@include filter-gradient(#478ce0, #0263db, vertical); // IE6-9
		@include background-image(linear-gradient(top,  #478ce0 0%,#1168db 100%,#0263db 100%));
  } 
}



body {
  background-color: #e6f2f7; // Old browsers
  @include filter-gradient(#e6f2f7, #a0d8ef, horizontal); 
  @include background-image(radial-gradient(center, circle cover,  #e6f2f7 0%,#a0d8ef 100%));

}

.viewport {
  margin: 10px auto 0;
  width: 500px;
}