CSS code optimization on Bitrix. How to do it right?

Question

css

Hello. The task is to optimize the site so that it loads quickly, without frills, save space without harming the external wrapper and functionality.
Bitrix has code minimization, but it does not seem to remove unused styles. Audit through the developer's console gave out as many as 6300+ unused styles, of which 50% are in kernel.css (in which 100% of the styles are not used) what can I do? Where can I turn it off and where are styles generally edited and how are they rebuilt in bitrix/cache? Is it automatic or do I need to do something?
And why are there two bootstraps in Bitrix. One normal other ".min"
Before that, I had to deal with the Yii Framework. There, the collector immediately eliminates everything superfluous. I would be glad for any hints, for me it is a dark forest.

Answer 1

Try the module - Bitrix has several on the market.
I like this one https://marketplace.1c-bitrix.ru/solutions/ammina.... I liked it - not only CSS - it optimizes everything

Answer 2

There is a good module for CSS: https://marketplace.1c-bitrix.ru/solutions/gorokho...