<table style="border-collapse:collapse;font-family:sans-serif;font-size:1em">
<thead>
<tr><th>A</th></tr>
</thead>
<tbody>
<tr><td style="font-weight:bold;background-color:#f0f0f0">First</td></tr>
<tr><td>1</td></tr>
<tr><td>2</td></tr>
<tr><td style="font-weight:bold;background-color:#f0f0f0">Second</td></tr>
<tr><td>3</td></tr>
</tbody>
</table>