What to focus on when layout support android 4.2?

Question

css

Hello. There is a task to make up n'th number of layouts. There is one caveat, you need support for android 4.2, webview. If anyone has come across, please explain what to focus on, what to read, maybe there are useful links? Is it possible to use after and before pseudo-classes?

Answer 1

maximum validity in the code and standards, less of any mega-super-crutches that the browser will understand in its own way. before and after are quite working everywhere, like even on an ancient donkey.