CSS3 实现图片上浮动画（转载）

CSS3 实现图片上浮动画

.gist {
width:220px;
height:130px;
background-image: url(2.jpg);
background-repeat:no-repeat;
border:5px solid green;
background-position:50% 50%;
transition:background-position 2s;
-moz-transition:background-position 2s; /* Firefox 4 */
-webkit-transition:background-position 2s; /* Safari and Chrome */
-o-transition:background-position 2s; /* Opera */
}

.gist:hover {
background-position: 50% -100px;
}
<div class="gist"></div>

图片水平垂直居中:
background-position:50% 50%;