What is the problem, is the long page of the site lags due to CSS?

Question

css

Good evening, tell me what could be the problem and how to fix it: 1) There is an HTML
page of the site, a very long page, it has a lot of elements displayed in a loop
fast scrolling down the white screen and blunts the browser (sometimes the page drops out altogether and the pancakes are shown), by poking and line-by-line disabling line by line of JS files and CSS files, it was revealed that everything is happening due to the CSS file

Tell me why this can happen, maybe this connected with the recalculation of the height of the blocks or something from this series, I feel that everything is going there, but where more specifically, can you tell me, I will be grateful!

Answer 1

The problem is solved, the reason why the browser did not have enough RAM and the document was shown for a long time, in one line of code, so I did not understand why, but apparently due to dynamically calculated block sizes

Answer 2

oops, this is if there is not enough operatives. on the mobile, remove some of the data. you can put a preloader