Centring divs is now an out of date joke, grandad, get with it. Flex box ruined it. Seriously, I wonder what the modern equivalent is? Using dev tools to find

Centring divs is now an out of date joke, grandad, get with it. Flex box ruined it. Seriously, I wonder what the modern equivalent is? Using dev tools to find the source of an unwanted space? What do you mean property X is inherited but only from the last positioned ancestor with a flex size of pi and a negative z index?