<div class="m-demo">

    <table>

        <thead>

           <tr><th>定宽a</th><th>定宽b</th><th>定宽c</th><th>最后列不定宽d</th></tr>

        </thead>

    </table>

    <div class="scroll">

        <table>

            <tbody>

                <tr><td>定宽a</td><td>定宽b</td><td>定宽c</td><td>最后列不定宽d</td></tr>

                <tr><td>定宽a</td><td>定宽b</td><td>定宽c</td><td>最后列不定宽d</td></tr>

                <tr><td>定宽a</td><td>定宽b</td><td>定宽c</td><td>最后列不定宽d</td></tr>

                <tr><td>定宽a</td><td>定宽b</td><td>定宽c</td><td>最后列不定宽d</td></tr>

                <tr><td>定宽a</td><td>定宽b</td><td>定宽c</td><td>最后列不定宽d</td></tr>

                <tr><td>定宽a</td><td>定宽b</td><td>定宽c</td><td>最后列不定宽d</td></tr>

            </tbody>

        </table>

    </div>

</div>

/* 预览辅助样式 */

body{margin:20px;}

html,body,h1,h2,h3,h4,h5,h6,div,dl,dt,dd,ul,ol,li,p,blockquote,pre,hr,figure,table,caption,th,td,form,fieldset,legend,input,button,textarea,menu{margin:;padding:;}

header,footer,section,article,aside,nav,hgroup,address,figure,figcaption,menu,details{display:block;}

table{border-collapse:collapse;border-spacing:;}

/* 表头固定内容滚动的表格  */

.m-demo{margin:  20px;line-height:18px;}

.m-demo .scroll{max-height:116px;border:1px solid #ddd;border-top:;overflow-y:auto;}

.m-demo table{width:%;table-layout:fixed;}

.m-demo th,.m-demo td{width:100px;padding:10px;border:1px solid #ddd;}

.m-demo th{font-weight:bold;background:#eee;}

.m-demo thead th:last-child,.m-demo tbody td:last-child{width:auto;}

.m-demo tbody tr:nth-child(2n){background:#fafafa;}

.m-demo tbody tr:first-child td{border-top:;}

.m-demo tbody tr:last-child td{border-bottom:;}

.m-demo tbody tr td:first-child{border-left:;}

.m-demo tbody tr td:last-child{border-right:;}