@jmaag

I am able to fix this by changing the box-sizing rule:

td .claro-details {
  box-sizing: border-box;
}

To avoid creating a sub-theme I attach it in a module:

/**
 * Implements hook_page_attachments()
 */
function MODULE_NAME_page_attachments(array &$attachments) {
  if (\Drupal::service('router.admin_context')->isAdminRoute()) {
    $attachments['#attached']['library'][] = 'MODULE_NAME/admin-theme';
  }
}