DomDocument检查网站是否有响应式设计

Question

The last thing i need to do for my scan is: checking if the website that i'm scanning is responsive.

I've tried to check via if($node->getAttribute('class')=='row') {but this doesn't work. Is there some way i can check if the website is responsive?

$responsive = $dom->getElementsByTagName('div');

I'm using Laravel 5.4 and DomDocument.

foreach ($responsive as $node) {
  if($node->getAttribute('class')=='row') {
   echo "Is responsive";
   }
}

I'm checking 'row' because a lot of people use Bootstrap or Foundation If you know a way that i can check with media queries, please let me know ^^,

Thanks,

Itvba