colgroup中col定义表格单元格宽度，table表格百分比自定义宽度
<html>
<style>
table {
border-collapse: collapse;
border: 2px solid #000;
width: 100%;
padding: 1px;
}
td {
padding: 5px;
}
</style>
<body>
<table width="1000px" border="1px" cellspacing="0" cellpadding="0">
<colgroup>
<col width="25%"/>
<col width="25%"/>
<col width="25%"/>
<col width="25%"/>
</colgroup>
<tr>
<td>11111</td>
<td>22222</td>
<td>33333</td>
<td>44444</td>
</tr>
</table>
</body>
</html>
