I have an issue with my responsive website.
I use an Iframe for my contact form so that when someone uses it and there is validation errors the server side codes responds and reloads in the same Iframe.
Everything works fine but if the iframe width is less than 300px it's changing to mobile view.
Note: site is built on Drupal 7.
on the page where you have your contact form you should disable media queries.
but really you should not use an iframe for this you should create some server side code to update on page not via an iframe.
Build it using php and Ajax similar to how this tutorial describes.
http://ajtroxell.com/build-a-simple-php-jquery-and-ajax-powered-contact-form/