<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
*{margin: 0;padding: 0;}
ul{list-style: none;}
.box{width: 500px;height: 500px;border: 1px solid black;perspective: 300px;margin: 200px;}
ul{width: 100px;height: 100px;margin: 100px;position: relative;transform-style: preserve-3d;transition: 2s;transform-origin: center center -50px;}
li{width: 100px;height: 100px;position: absolute;opacity: 0.3;text-align: center;line-height: 100px;}
li:nth-child(1){background-color: red;left: 0;top: 0;}
li:nth-child(2){background-color: blue;left: 100;top: 0;transform-origin: left;transform: rotateY(90deg);}
li:nth-child(3){background-color: green;left: 0;top: 100;transform-origin: top;transform: rotateX(-90deg);}
li:nth-child(4){background-color: yellow;left: 0;top: -100;transform-origin: bottom;transform: rotateX(90deg);}
li:nth-child(5){background-color: purple;left: -100;top: 0;transform-origin: right;transform: rotateY(-90deg);}
li:nth-child(6){background-color: brown;left: 0;top: 0;transform: translateZ(-100px);}
.box:hover ul{transform: rotateY(360deg);}
</style>
</head>
<body>
<div class="box">
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
</ul>
</div>
</body>
</html>
而且backface-visibility: hidden;为什么不能给ul加而非得给li加？
