protected function getThemeAssistantStylesheet()
	{
		if (!$GLOBALS['objPage'] || !$GLOBALS['objPage']->getRelated('layout')) {
			return null;
		}
		if (!$stylesheets = $GLOBALS['objPage']->getRelated('layout')->external) {
			return null;
		}

		$stylesheets = \StringUtil::deserialize($stylesheets);
		foreach ($stylesheets as $stylesheet) {
			$file = \FilesModel::findByUuid($stylesheet);
			if ($file && $file->path && file_exists(TL_ROOT . '/' . $file->path . '.base')) {
				return $file->path . '.base';
			}
		}

		return null;
	}