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.