Once again, you do not need to know PHP or any other server-side programming language to build a professional looking website. And no one can convince me otherwise, since I have been in the website development business for over 25 years. This is not about dynamically generated content, but rather front-end design.
So, if you're still not convinced of the power of HTML5 and CSS3, take a look at some of the examples from awards sites like awwwards:
https://www.awwwards.com/websites/css3/Well - with all due respect - then you mean to download a ready made page? What does this have to do with designing a site without programming languages?
The site you referred to, I can call it a "service" whether it is free or not, but it has nothing to do is that you can program web pages without a "programming language", They are just already made websites by developers and the tool has UI allow you to edit the., A paid service can do all that for you. I just referred for OP to use paid service for a better result, but also thats not bad.