<html>
  <body>
    <style type="text/css">
      body {
        font-family: monospace;
        line-height: 1.5em;
      }
      th { text-align: left; }
      td, th { padding: .5em; }
      tr:hover td { background: yellow; }
      .text-right { text-align: right; }
    </style>
    <h2>We currently still have {{ placeholders|length }} placeholder(s)</h2>
    <table>
      <tr>
        <th>ID</th>
        <th>payment_date</th>
        <th class='text-right'>price</th>
        <th>Links</th>
      </tr>
      {% for invoice in placeholders %}
      <tr>
        <td>{{ invoice.code }}</td>
        <td>{{ invoice.payment_date }}</td>
        <th class='text-right'>{{ invoice.price }}</th>
        <td>
          <a href='{% url 'debugpanel_invoice_forcepreview' invoice.id %}'>Preview PDF</a>
          | <a href='{{ invoice.get_admin_url }}'>See in admin</a>
          | <a href='{{ invoice.get_absolute_url }}'>URL for user</a>
        </td>
      </tr>
      {% endfor %}
    </table>
  </body>
</html>

<html>
  <body>
    <style type="text/css">
      body {
        font-family: monospace;
        line-height: 1.5em;
      }
      th { text-align: left; }
      td, th { padding: .5em; }
      tr:hover td { background: yellow; }
      .text-right { text-align: right; }
    </style>
    <h2>We currently still have {{ placeholders|length }} placeholder(s)</h2>
    <table>
      <tr>
        <th>ID</th>
        <th>payment_date</th>
        <th class='text-right'>price</th>
        <th>Links</th>
      </tr>
      {% for invoice in placeholders %}
      <tr>
        <td>{{ invoice.code }}</td>
        <td>{{ invoice.payment_date }}</td>
        <td class='text-right'>{{ invoice.price }}</td>
        <td>
          <a href='{% url 'debugpanel_invoice_forcepreview' invoice.id %}'>Preview PDF</a>
          | <a href='{{ invoice.get_admin_url }}'>See in admin</a>
          | <a href='{{ invoice.get_absolute_url }}'>URL for user</a>
        </td>
      </tr>
      {% endfor %}
    </table>
  </body>
</html>

Use a '<td/>' instead of a '<th/>'
Use a '<td/>' instead of a '<th/>'
