Another neat trick is to generate your website on your own PC and only publish the static version.

You can publish static files to a CDN service, which costs very little compared to traditional hosting that includes a dynamic language and database.

A CDN is also usually distributed across the world and has cool features like built-in scalability and redundancy which means very little chance of outages, can deal with traffic spikes, and fast response no matter where the visitors are from.

This is also what I suggest. I moved from WordPress to Grav. It’s good, but a lot of work to customize.

Here’s a very useful resource of code snippets to make your website attractive and functional, without aCMS. https://www.w3schools.com/howto/default.asp

CSS can become tedious, especially if you are targeting mobile device and tablets and building this in plain HTML CSS and PHP is way too much work and the end result will probably still not be very responsive and won't look so great.

This approach is definitely an overkill and if the OP doesn't want to use this as an educational project I will strongly suggest not to go this route. Just use some of the tools the other has suggested here, like Grav, Hugo, etc.

I have done this, but instead of PHP, I have used Server Includes, which is a performant and simple way to add repeating headers and footers etc without extra dependecies. Nginx, Apache and Caddy all supports Server Includes, but with different syntax. I have used Caddys templating language, which I am most comfortable with.