Social Icons CSS3

HTML

<ul id="social">
        <li class="forrst"><a href=""><span>Forrst</span></a></li>
        <li class="dribbble"><a href=""><span>Dribble</span></a></li>
        <li class="twitter"><a href=""><span>Twitter</span></a></li>
        <li class="github"><a href=""><span>Github</span></a></li>
        <li class="linked-in"><a href=""><span>Linked-In</span></a></li>
        <li class="facebook"><a href=""><span>Facebook</span></a></li>
      </ul>

CSS

body{
  background: #222222;
}

#social{
  position:absolute;
  top:20px;
  left:20px;
}

#social li{
  height:45px;
  width:45px;
  float:left;
  margin:0 0 0 5px;
}

#social li a, #social li a span{
  display:block;
  height:45px;
  width:45px;
  overflow:hidden;
  text-indent:-99999px;
    
  -moz-transition: all 0.3s ease-out;  
  -o-transition: all 0.3s ease-out;  
  -webkit-transition: all 0.3s ease-out;  
  -ms-transition: all 0.3s ease-out;  
  transition: all 0.3s ease-out;
}

#social li a{
  position:absolute;
  top:0px;
  background-image:url(http://jcwd.com.au/super/secret/dev/shiz/images/social_overlay.png);
    
  box-shadow:0px 1px 2px rgba(0,0,0,0.5);
  -moz-border-radius-bottomleft: 6px;
  -moz-border-radius-bottomright: 6px;
  -webkit-border-bottom-left-radius:6px;
  -webkit-border-bottom-right-radius: 6px;
}

#social li a span{
  opacity:0.2;
  filter:alpha(opacity=20); 
  background-position:center center;
  background-repeat:no-repeat;
}

/*forrst*/
#social li.forrst a span{ background-image:url(http://jcwd.com.au/super/secret/dev/shiz/images/forrst.png); }
#social li.forrst a:hover{ background-color:#27481b; }

/*dribbble*/
#social li.dribbble a span{ background-image:url(http://jcwd.com.au/super/secret/dev/shiz/images/dribbble.png); }
#social li.dribbble a:hover{ background-color:#ea4c89; }

/*twitter*/
#social li.twitter a span{ background-image:url(http://jcwd.com.au/super/secret/dev/shiz/images/twitter.png);}
#social li.twitter a:hover{ background-color:#64d8ff; }

/*github*/
#social li.github a span{ background-image:url(http://jcwd.com.au/super/secret/dev/shiz/images/github.png); }
#social li.github a:hover{ background-color:#657c9c; }

/*linked in*/
#social li.linked-in a span{ background-image:url(http://jcwd.com.au/super/secret/dev/shiz/images/linked-in.png); }
#social li.linked-in a:hover{ background-color:#6bb4d5; }

/*facebook*/
#social li.facebook a span{...