table-列组

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>colgroup</title>
    <style>
        .engine{
            background-color: aquamarine;
        }
    </style>
</head>
<body>
<table border="1">
    <!--列组　-->
    <colgroup>
        <col class="browser">
        <col class="engine" span="2">
    </colgroup>
    <thead>
        <tr>
            <th>浏览器</th>
            <th>渲染引擎</th>
            <th>JavaScript 引擎</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <th>Chrome</th>
            <td>Blink</td>
            <td>V8</td>
        </tr>
        <tr>
            <th>Opera</th>
            <td>Blink</td>
            <td>V8</td>
        </tr>
        <tr>
            <th>Edge</th>
            <td>EdgeHTML</td>
            <td>Chakra</td>
        </tr>
    </tbody>
</table>
</body>
</html>
效果：