CSS에서 테이블에 행 번호 지정

<table>
  <thead>
    <tr>
      <th></th>
      <th>column1</th>
      <th>column2</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td></td>
      <td>foo</td>
      <td></td>
    </tr>
    <tr>
      <td></td>
      <td>bar</td>
      <td></td>
    </tr>
    <tr>
      <td></td>
      <td>baz</td>
      <td></td>
    </tr>
  </tbody>
</table>

table {
  counter-reset: rowCount;
}

table > tbody > tr {
  counter-increment: rowCount;
}

table > tbody > tr > td:first-child::before {
  content: counter(rowCount);
}