How to implement cross-browser page?

Question

css

The question is rather the correctness of the implementation of the cross-browser compatibility of the page.
The same responsive layout unfortunately looks different on the page.
My thoughts are as follows: on the server side, determine the type of browser and send a certain set of files. Perhaps there are other options.
How to solve a similar problem in other, simpler ways?

Answer 1

I typeset and initially look in FFox. Then on Chrome. Safari may have big problems, too. this thing counts the whole box model in its own way, IMHO! Browser stack helps (expensive, but what to do, you can’t keep up with all iOS)