Executing a PHP HTML-CSS container on top of various content management systems
I have created two PHP modules, one is a contact form module and one is a a sticky "call now" module.
I can access the contact form by
example.com/contact_form.php but in contrast,
example.com/call_now.php shouldn't be a standalone webpage, rather just a container for some HTML and CSS which I want to execute on top of every webpage in my website.
.html because it allows
includes which I use a lot).
How could I execute the PHP-formatted, HTML-CSS container on top of any content management system (CMS-agnostically) so that if tomorrow I will change the CMS from MediaWiki to Drupal, any user could still use the same sticky "call now" button?