css3动画垂直翻转180度

<ul class="flatflipbuttons">
<li><a href="http://www.w2bc.com" title="Search"><span class="icon-search"></span>
</a><b>Search</b></li>
<li><a href="http://www.w2bc.com"><span class="icon-gears"></span></a><b>Gears</b></li>
<li><a href="http://www.w2bc.com"><span class="icon-rss"></span></a><b>RSS</b></li>
<li><a href="http://www.w2bc.com"><span class="icon-twitter"></span></a><b>Twitter</b></li>
<li><a href="http://www.w2bc.com"><span class="icon-rocket"></span></a><b>Rocket</b></li>
</ul>
<br />
<br />
<ul class="flatflipbuttons second">
<li><a href="http://www.w2bc.com"><span>
<img src="imgs/rss-heart.png" /></span></a></li>
<li><a href="http://www.w2bc.com"><span>
<img src="imgs/twitter-heart.png" /></span></a></li>
<li><a href="http://www.w2bc.com"><span>
<img src="imgs/facebook-heart.png" /></span></a></li>
<li><a href="http://www.w2bc.com"><span>
<img src="imgs/google-heart.png" /></span></a></li>
<li><a href="http://www.w2bc.com"><span>
<img src="imgs/stumble-heart.png" /></span></a></li>
4000
</ul>

ul.flatflipbuttons
{
margin: 0;
padding: 0;
list-style: none;
-webkit-perspective: 10000px; /* larger the value, the less pronounced the 3D effect */
-moz-perspective: 10000px;
perspective: 10000px;
}

ul.flatflipbuttons li
{
margin: 0;
display: inline-block;
width: 100px; /* dimensions of buttons. */
height: 100px;
margin-right: 15px; /* spacing between buttons */
background: white;
text-transform: uppercase;
text-align: center;
}

ul.flatflipbuttons li a
{
display: table;
font: bold 36px Arial; /* font size, pertains to icon fonts specifically */
width: 100%;
height: 100%;
margin-bottom: 4px;
color: black;
background: #3B9DD5;
text-decoration: none;
outline: none;
-webkit-transition: all 300ms ease-out; /* CSS3 transition. Last value is pause before transition play */
-moz-transition: all 300ms ease-out;
transition: all 300ms ease-out;
}

ul.flatflipbuttons li:nth-of-type(1) a
{
color: white;
background: #3B9DD5;
}

ul.flatflipbuttons li:nth-of-type(2) a
{
background: #A1CD3A;
}

ul.flatflipbuttons li:nth-of-type(3) a
{
background: #80C5EC;
}

ul.flatflipbuttons li:nth-of-type(4) a
{
color: white;
background: #635746;
}

ul.flatflipbuttons li:nth-of-type(5) a
{
background: #F2C96D;
}

ul.flatflipbuttons li a span
{
-moz-box-sizing: border-box;
-webkit-box-sizing: border-box;
box-sizing: border-box;
display: table-cell;
vertical-align: middle;
width: 100%;
height: 100%;
-webkit-transition: all 300ms ease-out; /* CSS3 transition. */
-moz-transition: all 300ms ease-out;
transition: all 300ms ease-out;
}

ul.flatflipbuttons li b
{
/* CSS for text beneath button */
display: block;
position: relative;
width: 100%;
opacity: 0;
-webkit-transition: all 300ms ease-out 0.2s; /* CSS3 transition. 0.2s delay */
-moz-transition: all 300ms ease-out 0.2s;
transition: all 300ms ease-out 0.2s;
}

ul.flatflipbuttons li a img
{
/* CSS for image if defined inside button */
border-width: 0;
vertical-align: middle;
}

ul.flatflipbuttons li:hover a
{
-webkit-transform: rotateY(180deg); /* flip horizontally 180deg*/
-moz-transform: rotateY(180deg);
transform: rotateY(180deg);
background: #c1e4ec; /* bgcolor of button onMouseover*/
-webkit-transition-delay: 0.2s;
-moz-transition-delay: 0.2s;
transition-delay: 0.2s;
}

ul.flatflipbuttons li:hover a span
{
color: black; /* color of icon font onMouseover */
-webkit-transform: rotateY(180deg);
-moz-transform: rotateY(180deg); /* flip horizontally 180deg*/
transform: rotateY(180deg);
-webkit-transition-delay: 0.2s;
-moz-transition-delay: 0.2s;
transition-delay: 0.2s;
}

ul.flatflipbuttons li:hover b
{
opacity: 1;
}

/* CSS for 2nd menu below specifically */

ul.second li a
{
background: #eee !important;
}

ul.second li a:hover
{
background: #ddd !important;
}