How to transfer a static site to the engine?

Question

CMS

Made a website. The client thought that any site in the world has an admin panel where you can edit the site. Although, when ordering, I explained to him that only I can edit a static site. Well, he seemed to think that I was just deceiving him or that he was smarter than me, I don’t know what he was thinking at all. In general, he wants me to transfer this to the engine. Advise the engine to which you can easily transfer the html site. To be honest, it seems to me an impossible task, because it seems that you need to completely rethink the site in order to make a template out of it, and then fill it with content. I've looked at Joomla and WordPress and both seem unrealistically complex to me. In WP, I still have not figured out how to correctly add style, script files. And Joomla seems to me just unrealistically heavy for such a site, I tried for 10 minutes to figure out how to create a link in the menu to a static page. Advise what to do? Which engine to choose? Preferably with a link to a guide on how to make a template. Thanks in advance.
Update : Thank you all, the site was still transferred to wordpress, when I sat for 2-3 hours without getting up, I realized that it was easy.

Answer 1

Laconically and clearly, no questions should arise ...
PS if there is a layout, watch only the last 2 lessons, it will take 2 hours to install your layout

Answer 2

Why move to CMS?
Make him a simple admin panel, or put some kind of script, like this:
u-administrator.com (which first came up in Google)

Answer 3

1. laravel
   They are connected as always) In the template file or in the controller ( MVC is used ).
   Select the dynamic part, which needs to be changed through the PU, leave the statics in the template.
   Download a ready-made free template and use it as an example to make your own template.