利用css3 translate完美实现表头固定效果

<div class="box">
    <table>
        <thead>
            <tr>
                <th>1</th>
                <th>2</th>
                <th>3</th>
                <th>4</th>
                <th>5</th>
                <th>6</th>
                <th>7</th>
                <th>8</th>
                <th>9</th>
                <th>10</th>
                <th>11</th>
                <th>12</th>
                <th>13</th>
                <th>14</th>
                <th>15</th>
            </tr>
        </thead>
        <tbody>
            <script>
            var tr = '';
            for(var i=0; i<15; i++) {
                tr += '<tr>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                        <td>'+i+'</td>                    </tr>';
            }
            document.write(tr);
            </script>                
        </tbody>
    </table>
</div>

<style>
*{ margin: 0; padding: 0; list-style: none;}
.box {
    width: 300px;
    height: 300px;
    margin: 50px auto 0;
    overflow: auto;
}
.box table{
    width: 100%;
    border-collapse: collapse;
    border-right: 1px solid #ccc;
    border-top: 1px solid #ccc;
    text-align: center;
}
.box table thead {
    background-color: #ccc;
}
.box table th,
.box table td {
    padding: 8px 10px;
    border-left: 1px solid #ccc;
    border-bottom: 1px solid #ccc;
    white-space: nowrap;
}
</style>

<script>
window.onload = function() {
    var $ = document.querySelector.bind(document);
    var boxEle = $('.box');
    boxEle.addEventListener('scroll', function(e) {
        this.querySelector('thead').style.transform = 'translate(0, '+this.scrollTop+'px)';
    });
}
</script>