CSS3 transform 立体导航栏demo效果：

<!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;
      list-style: none;
    }
    body {
      background-color: dodgerblue;
      font-size: 20px;
    }
    ul {
      width: 900px;
      margin: 100px auto;
      list-style: none;
      position: relative;
    }
    li {
      float: left;
      width: 180px;
      height: 80px;
      cursor: pointer;
    }
    li span { 
      float: left;
      height: 80px;
      background-color: #ccc;
    }
    li .left {
      width: 30px;
      transform-origin: left;
    }
    li .right {
      width: 30px;
      transform-origin: right;
    }
    li .center {
      width: 120px;
      line-height: 80px;
      text-align: center;
    }
    li:hover .left {
      transform:  skew(0, -30deg);
      background-color: rgb(154, 148, 148);
    }
    li:hover .right {
      transform:  skew(0, 30deg);
      background-color: rgb(154, 148, 148);
    }
    li:hover .center {
      transform:  translateY(-17px);
      text-shadow: 5px 5px 3px #333;
      box-shadow: 0 15px 40px -4px #666;
    } 
    /* ul 前后添加空白区域 */
    ul::before, ul::after {
      content: "";
      width: 80px;
      height: 80px;
      position: absolute;
      left: -80px;
      top: 0;
      background-color: #ccc;
    }
    ul::after {
      /* 上面设置了left, 现在需要设置右边的时候得释放它的左边依赖，否则右边不会生效 */
      left: auto;
      right: -80px;
    }
  </style>
</head>
<body>
  <ul>
    <li>
      <span class="left"></span>
      <span class="center">小说阅读器</span>
      <span class="right"></span>
    </li>
    <li>
      <span class="left"></span>
      <span class="center">小说阅读器</span>
      <span class="right"></span>
    </li>
    <li>
      <span class="left"></span>
      <span class="center">小说阅读器</span>
      <span class="right"></span>
    </li>
    <li>
      <span class="left"></span>
      <span class="center">小说阅读器</span>
      <span class="right"></span>
    </li>
    <li>
      <span class="left"></span>
      <span class="center">小说阅读器</span>
      <span class="right"></span>
    </li>
  </ul>
</body>
</html>
demo 效果：