My embedded form doesn't work properly when going to 'phone' mode

[Alan Sh]

I have a very simple page - it has a heading and then a rectangular shape that has a form (iframe) inside it. I have a desktop and a mobile view of the form

However, when I preview it or export it as .htm, it doesn't work properly with any browser. What have I done wrong?

I've attached a zip file with my .web file inside and also the resultant .htm file from page 'formtest'. Would anyone have time to have a quick look?

cheers

Alan