效果
 
 

 
 
 原理
 
 
- 提示内容的定位:子绝父相
 - 鼠标悬浮前,提示内容
visibility: hidden; - 通过 
:hover 触发鼠标悬浮样式,提示内容变为 visibility: visible; 
 
 
 代码
 
 
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>CSS 模拟 HTML title 效果(兼容旧浏览器)</title>
    <style>
      
      .tipBox {
        position: relative;
        display: inline-block;
      }
      
      .tipBox .tipContent {
        position: absolute;
        top: 100%;
        left: 50%;
        color: rgb(105, 100, 100);
        background-color: #f9f9f9;
        border: 1px solid #ccc;
        border-radius: 2px;
        font-size: 12px;
        padding: 2px 4px;
        box-shadow: 3px 3px 3px rgba(0, 0, 0, 0.3);
        white-space: nowrap;
        visibility: hidden;
      }
      
      .tipBox:hover .tipContent {
        visibility: visible;
      }
    </style>
  </head>
  <body style="padding: 40px">
    <h1>title 效果</h1>
    <div title="12345678">12345678</div>
    <h1>css 模拟 title 效果</h1>
    <div class="tipBox">
      12345678
      <div class="tipContent">12345678</div>
    </div>
  </body>
</html>