Need help customizing CSS for product detail page on Shopify-based website

I have a client who is insisting on having a completely different layout for her product detail pages (on a Shopify based website) when viewing it on a mobile device:

http://testing2connect.myshopify.com/collections/frontpage/products/the-ideaboard-original-backer-pricing

Using this example product detail page as a reference  -- what she'd like is to have it so that when you view the page on a mobile device (ie: iphone in portrait mode), .. the different modules would be re-ordered as follows:

1) Product name & price
2) Quantity field & Add to Cart button
3) Product image(s)
4) Product description
5) Product reviews
6) Related products
7) Etc, etc.

I tried explaining to her that responsive web design requires that you think in terms of "individual columns of content wrapping underneath eachother as needed" .. but she didn't seem to understand what I was taking about.

I'm looking to find out if a completely different layout is even possible to achieve within this context, and if so, ... how.  

If it is NOT posssible to achieve a completely different layout within this context, I need to be able to provide a logical, technical explanation as to why it is not possible.  

Please advise.

Thanks,
- Yvan