<!DOCTYPE html>
<html>
  <meta charset="utf-8">
  <link rel="author" title="David Shin" href="mailto:dshin@mozilla.com">
  <link rel="author" title="Mozilla" href="http://www.mozilla.org/">
  <link rel="help" href="https://html.spec.whatwg.org/#tables-2">

  <style>
  table {
    font-size: 15px;
    border: 1px solid green;
    margin-bottom: 5px;
  }

  th {
    width: 150px;
    border: 1px solid blue;
  }

  td {
    border: 1px solid purple;
  }
  </style>

  <body>
    <table>
      <tr>
        <th style="text-align: center;">A</th>
      </tr>
      <tr>
        <td style="text-align: start;">A</td>
      </tr>
    </table>
    <table>
      <tr>
        <th style="text-align: end;">A</th>
      </tr>
      <tr>
        <td style="text-align: end;">A</td>
      </tr>
    </table>
    <table>
      <tr>
        <th style="text-align: start;">A</th>
      </tr>
      <tr>
        <td style="text-align: start;">A</td>
      </tr>
    </table>
  </body>
</html>
