HTML : 테이블의 전체 열에 스타일 적용

<table width="100%">
    <colgroup>
        <col style="width:40%;" />
        <col style="width:60%;" />
    </colgroup>
    <thead>
        <tr>
            <td>
               Column 1
               <!--This column will have 40% width-->
            </td>
            <td>
               Column 2
               <!--This column will have 60% width-->
            </td>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>Cell 1</td>
            <td>Cell 2</td>
        </tr>
    </tbody>
</table>

Note: The <colgroup> tag must be a child of a <table> element, after any <caption> elements and before any <thead>,<tbody>, <tfoot>, and <tr> elements.