How to set button position in CSS so that it remained fixed in its position from any screen size?

Question

I have done a program in css and html using button on my tab but when I opened the same program from my mobile the buttons were overlapping on each other.
https://code.sololearn.com/WC62fZqa7hhu/?ref=app

Answer 1

good attempt
Don't hardcode the top and left, use grid system instead
for elements of same styles, use the same class name.
fix :
https://code.sololearn.com/WTA5IxErR6DX/?ref=app
tutorials about grid :
https://code.sololearn.com/WTnC2BJ6tJKl/?ref=app
This series containing 6 lessons teach you how to code a MC quiz from beginning to end:
https://code.sololearn.com/W5mojZU2ssHo/?ref=app
https://code.sololearn.com/WKKkpq0efxai/?ref=app