## Transition 示例 ```css img{ height:15px; width:15px; display: block; margin:15px auto; transition:1s height; } img:hover{ height: 450px; width: 450px; } ``` ***** ##### 参考 [css动画教程](http://www.ruanyifeng.com/blog/2014/02/css_transition_and_animation.html)