public function computeForStyle($html)
{
if (1 !== preg_match_all('/<style[^>]*>/i', $html, $m)) {
throw new \InvalidArgumentException('Invalid script, you should use a single <style> tag.');
}
preg_match('/^\\s*<style[^>]*>((?s).*)<\\/style>\\s*$/i', $html, $matches);
if (!isset($matches[1])) {
throw new \InvalidArgumentException('Invalid script, no <style> tag found.');
}
return $this->compute($matches[1]);
}