Just put the content on the page, with each section left to size itself based on however-much content is in it, instead of giving each section its own scrollbar at least?
I remember doing this 15 years ago.
Today this is a problem that was solved dozens of times, from Bootstrap, to Zurb and Tailwind - with productivity, accessibility and variety of devices and screen-sizes in mind.
Your website is unpleasant to use and scroll. It feels you're reinventing the wheel just for the sake of it?
It’s a lot easier to start with a good, semantic html structure and come up with exactly the CSS that one needs, rather than continually fight a system aimed at no one in particular.
Not to mention the bloat of unnecessary CSS/JS that you don’t actually need.