{# A page break, carried by a table ROW.

   Containers emit `tr` blocks, so a page cannot wrap them in a div without
   producing invalid markup inside the body table. CSS break properties do
   not apply to a `td` either -- a table-cell is not a block box -- so the
   declaration lands on the `tr`, which CSS 2.1 does allow. The nested table
   is what gives those child rows somewhere valid to live; it is the frame's
   own width, so every column width computed from the frame still holds.

   Both spellings are emitted: `break-before` is the current property and
   `page-break-before` the CSS 2.1 one every print engine still honours.

   The ground is the container idiom, not a special case: a caller's
   `background_color` if they set one, the theme's surface otherwise. Jinja's
   `default` substitutes only for an *undefined* name, which is exactly how
   `_base_context` injects the field -- present when set, absent when not. #}
<tr{% if break_before or break_after %} style="{% if break_before %}break-before:page; page-break-before:always;{% endif %}{% if break_after %} break-after:page; page-break-after:always;{% endif %}"{% endif %}>
  <td style="padding:0;">
    <table role="presentation" width="{{ size.frame.width }}" cellpadding="0" cellspacing="0"
           border="0" style="width:{{ size.frame.width }}px; background-color:{{ background_color | default(theme.palette.surface) }};"
           bgcolor="{{ background_color | default(theme.palette.surface) }}">
{{ sections_html }}
    </table>
  </td>
</tr>