React native doesn't really use css - there are no .css files, no cascading either. It's more like a style engine that uses a subset of css ideas as a starting point.
It uses flex-box (and only flex-box) for layout, adds some convenient shorthands - marginVertical, marginHorizontal, and does some surprising (but useful) things like has transform take a JS array of key value pairs - https://reactnative.dev/docs/transforms#transform
It uses flex-box (and only flex-box) for layout, adds some convenient shorthands - marginVertical, marginHorizontal, and does some surprising (but useful) things like has transform take a JS array of key value pairs - https://reactnative.dev/docs/transforms#transform