No, I can't do what I used to do again, you'll ask why?
- First, I don't change rules in main css
- But for more than 6 months I have been working on a project where
custom css is the only css that is loaded in the head, main css is loaded before closing the body tag.
- in the custom css content, all the framework and responsive file names are found, and some others. But with numbering, for example 1fr_global.css or 2res_ responsive.css, etc.
- In these new files, I move used rules when analyzing site pages, i.e. in the main css all the rules are contained (as they have been moved they are stopped from execution only) - or here in the main css all the rules are loaded that are unused effectively when loading the site pages.
This new layout greatly speeds up site loading.
The custom.css file also exists in custom directory and there are my customizations - and as you know, the rules there are the latest and are executed by the browser as they are there.
Since IPS introducing restrictions for visibility on css main, I abandoned a project where mobile view loads on PSI test data between 88 and 94 points depending on server busyness.
And believe me - during the time I was working on this project - several updates were completed - without any site issues...