在《JS模拟百度分享侧边栏效果》一文中对于Div区块的运动通过JS实现了鼠标移入滑出显示，鼠标移出滑入隐藏的效果。其实在CSS3中通过transition属性就可以较为轻松实现。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
<style>
html,
body {
margin: 0;
padding: 0;
}
#div1 {
width: 150px;
height: 200px;
background: green;
position: absolute;
left: -150px;
top: calc(50% - 100px);
transition:left 0.5s linear ;
}
#div1 span {
width: 20px;
height: 60px;
line-height: 20px;
right: -20px;
top: 70px;
background: blue;
position: absolute;
}
/* 补充代码*/
</style>
</head>
<body>
<div id='div1'>
<span>分享到</span>
</div>
</body>
</html>
参考代码：
html,
body {
margin: 0;
padding: 0;
}
#div1 {
width: 150px;
height: 200px;
background: green;
position: absolute;
left: -150px;
top: calc(50% - 100px);
/*补充代码 */
transition: left 0.5s linear;
}
#div1 span {
width: 20px;
height: 60px;
line-height: 20px;
right: -20px;
top: 70px;
background: blue;
position: absolute;
}
/* 补充代码 */
#div1:hover {
left: 0;
transition: left 0.5s linear;
}