private function add_css_vars(HTMLElement $element, array &$tpl_vars)
{
$tpl_vars['C_CSS_CLASSES'] = $element->has_css_class();
$tpl_vars['CSS_CLASSES'] = $element->get_css_class();
$tpl_vars['C_CSS_STYLE'] = $element->has_css_style();
$tpl_vars['CSS_STYLE'] = $element->get_css_style();
}