Responsive not working on mobile

Hi all – I apologize in advance if this is a ridiculous question (I sense it might be) or if it’s been addressed already in the forum (I searched but failed to find my resolution).

I am currently working with Customizr and I really like my test pages on desktop and on tablet. But, for some reason, I am not getting the responsive version on my phone (iPhone). Instead, I am getting a very basic page with none of the theme design (seems like maybe it’s a default delivery from WordPress).

I know I’m doing something stupid – can anyone tell me what stupid thing I’m doing that is causing this?

Thanks for the help.

My test site – http://www.robkazart.com/rpktest