My question is about responsive designs (HTML + CSS). Does it matter if I use a different elements for desktop and mobile versions of my site? I mean that my page isn't really responsive, it only checks the user-agent using PHP code, and if it's a desktop user it includes
desktoparticle.php, if not it will include
These two PHP files are different, they have a different structure and different styles, also a different order of elements, but they are both under the same domain; this functionality is under the same URL also.
So my question is, would Google get confused, and is this something bad to do? Would this affect my SEO?