<button>Toggle <code>caption-side</code> position</button>

<table>
  <caption>This is a table caption example</caption>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
  <tr>
    <td>Example text</td>
    <td>Example text</td>
    <td>Example text</td>
  </tr>
</table>

body {
  margin: 20px;
}

button {
  display: block;
  margin: 0 auto 20px;
}

table {
  min-width: 80%;
  margin: auto;
  border-collapse: collapse;
}

caption {
  background: #ddd;
  padding: 10px;
}

.cap-bottom {
  caption-side: bottom;
}

td {
  text-align: center;
  border: solid 2px #ccc;
  padding: 5px;
}

document.querySelector('button').addEventListener('click', function () {
  document.querySelector('caption').classList.toggle('cap-bottom');
}, false);