public function bodyClassFunc($classes)
    {

        $header = $this->grav['page']->header();
        $body_classes = $header->body_classes ?? '';

        foreach ((array)$classes as $class) {
            if (!empty($body_classes) && Utils::contains($body_classes, $class)) {
                continue;
            }

            $val = $this->config->get('theme.' . $class, false) ? $class : false;
            $body_classes .= $val ? ' ' . $val : '';
        }

        return $body_classes;
    }