Drupal 7: Add Page Manager info to html body classes. Add to THEME_preprocess_html().
$page = page_manager_get_current_page();
if ($page) {
$vars['classes_array'][] = 'page-manager';
$vars['classes_array'][] = 'page-manager-' . $page['name'];
if (isset($page['handler']->conf['display']->layout)) {
$vars['classes_array'][] = 'page-manager-layout-' . $page['handler']->conf['display']->layout;
}
}