public function css($path, array $options = [])
    {
        $options += ['once' => true, 'block' => null, 'rel' => 'stylesheet'];

        if (is_array($path)) {
            $out = '';
            foreach ($path as $i) {
                $out .= "\n\t" . $this->css($i, $options);
            }
            if (empty($options['block'])) {
                return $out . "\n";
            }

            return null;
        }

        if (strpos($path, '//') !== false) {
            $url = $path;
        } else {
            $url = $this->Url->css($path, $options);
            $options = array_diff_key($options, ['fullBase' => null, 'pathPrefix' => null]);
        }

        if ($options['once'] && isset($this->_includedAssets[__METHOD__][$path])) {
            return null;
        }
        unset($options['once']);
        $this->_includedAssets[__METHOD__][$path] = true;
        $templater = $this->templater();

        if ($options['rel'] === 'import') {
            $out = $templater->format('style', [
                'attrs' => $templater->formatAttributes($options, ['rel', 'block']),
                'content' => '@import url(' . $url . ');',
            ]);
        } else {
            $out = $templater->format('css', [
                'rel' => $options['rel'],
                'url' => $url,
                'attrs' => $templater->formatAttributes($options, ['rel', 'block']),
            ]);
        }

        if (empty($options['block'])) {
            return $out;
        }
        if ($options['block'] === true) {
            $options['block'] = __FUNCTION__;
        }
        $this->_View->append($options['block'], $out);
    }