答案 0 :(得分:1)
我编辑了你的小提琴:https://jsfiddle.net/fqsLaxzL/2/
table {
border: solid 1px black;
}
.myform table:FIRST-CHILD td { color: red }
<form class="myform">
<table>
<tr>
<td>this</td>
<td>this</td>
<td>
<table>
<tr>
<td>this one too</td>
<td>this one too</td>
</tr>
</table>
</td>
</tr>
</table>
<table>
<tr>
<td>...</td>
</tr>
</table>
<table>
<tr>
<td>...</td>
</tr>
</table>
</form>