我有下表

<table>
        <tr>
            <td>1st</td>
            <td>Anne Wright &amp; Steve Wright</td>
            <td>510 VPs</td>
        </tr>
        <tr>
            <td>2nd</td>
            <td>Ian Bruce &amp; Lyn Hilton</td>
            <td>472 VPs</td>
        </tr>
        <tr>
            <td>3rd</td>
            <td>Anne Morris &amp; Lucy Pathan</td>
            <td>469 VPs</td>
        </tr>
        <tr>
            <td>4th</td>
            <td>Mike Ayers &amp; Mike Gould</td>
            <td>426 VPs</td>
        </tr>
        <tr>
            <td>5th</td>
            <td>Alison Nichols &amp; Simon Stokes</td>
            <td>409 VPs</td>
        </tr>
        <tr>
            <td>6th</td>
            <td>Brian Stockdale &amp; Sheila Stockdale</td>
            <td>406 VPs</td>
        </tr>
        <tr class="relegated">
            <td>7th</td>
            <td>Pauline Dignan &amp; Val Rees</td>
            <td>349 VPs</td>
        </tr>
        <tr class="relegated">
            <td>8th</td>
            <td>Alan Lord &amp; John Thompson</td>
            <td>319 VPs</td>
        </tr>
    </table>

我想在包含類& quot降級& quot。

我知道我需要在孩子身上應用邊框& lttd & gt標簽，而不是& lttr & gt

我試過了

.relegated:nth-child(1) td {
            border-top: 1px dashed red;
        }

但是我什么也沒得到。做

tr:nth-child(7) td {
            border-top: 1px dashed red;
        }

確實有效。但我想以班級為基礎(因為這是一個聯賽表，你不能從底部分區降級)。

# # #用那個。 :第n個子級(類名的1個)

tr:nth-child(1 of .relegated) td{
  border-top: 1px dashed red;
}

<table id="table">
  <tbody>
      <tr>
            <td>1st</td>
            <td>Anne Wright &amp; Steve Wright</td>
            <td>510 VPs</td>
        </tr>
        <tr>
            <td>2nd</td>
            <td>Ian Bruce &amp; Lyn Hilton</td>
            <td>472 VPs</td>
        </tr>
        <tr>
            <td>3rd</td>
            <td>Anne Morris &amp; Lucy Pathan</td>
            <td>469 VPs</td>
        </tr>
        <tr>
            <td>4th</td>
            <td>Mike Ayers &amp; Mike Gould</td>
            <td>426 VPs</td>
        </tr>
        <tr>
            <td>5th</td>
            <td>Alison Nichols &amp; Simon Stokes</td>
            <td>409 VPs</td>
        </tr>
        <tr>
            <td>6th</td>
            <td>Brian Stockdale &amp; Sheila Stockdale</td>
            <td>406 VPs</td>
        </tr>
        <tr class="relegated">
            <td>7th</td>
            <td>Pauline Dignan &amp; Val Rees</td>
            <td>349 VPs</td>
        </tr>
        <tr class="relegated">
            <td>8th</td>
            <td>Alan Lord &amp; John Thompson</td>
            <td>319 VPs</td>
        </tr>     
  </tbody>      
</table>