css/css-tables/border-collapse-empty-cell.html

<!doctype HTML>
<title>Collapsed borders of empty cells are painted</title>
<link rel="author" href="atotic@chromium.org">
<link rel="match" href="border-collapse-empty-cell-ref.html">
<link rel="help" href="https://stackoverflow.com/questions/18758373/why-do-the-css-property-border-collapse-and-empty-cells-conflict">
<style>
  table {
    border-collapse: collapse;
    empty-cells: hide;
  }
  td {
    width:50px;
    height:50px;
    border: 10px solid gray;
  }
</style>
<table>
  <tr>
    <td></td>
    <td></td>
  </tr>
  <tr>
    <td></td>
    <td></td>
  </tr>
</table>