I write web-based software and simple website ("Home", "Who we are", "Contact").

For a simple website I'm using a covered GPL v3 framework. The user surf the website, send an email, take info, etc. I repeat: simple website, not a Joomla or Wordpress.

1) Will the website be covered with the GPL? I don't modify the framework. I'm using his classes in other classes... (OOP).

2) For the point 1, if yes, do I need to add (e.g. in the footer) name of framework and his link?

3) I must permit download of entire website to study code (nothing that a programmer has interest in)? E.g. placing it in Github?

4) If 2 is NO, how you can "understand" that we use that framework? In effect no php lines are exposed to the browser... You cannot understand that when you push "Send email" the site is calling $this->send($email). If you write me an email "Are you using XXX framework"? I can answer NO.