<table>
  <thead>
    <tr>
      <th>A</th>
      <th>B</th>
      <th>C</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>2</td>
      <td>3</td>
    </tr>
    <tr>
      <td>10</td>
      <td>20</td>
      <td>30</td>
    </tr>
  </tbody>
</table>
table {
  display: grid;
  border-collapse: collapse;
  min-width: 100%;
  grid-template-columns: repeat(3, 1fr);
}

thead,
tbody,
tr {
  display: contents;
}

th, td {
  text-align: center;
  border-bottom: 1px solid black;
}

External CSS

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External JavaScript

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