How to remove compatibility issues in web codes?

Question

I had made a notes app. But when I opened it on my windows 7 it wasn't working. Will anyone please tell me how to avoid compatibility issues?

Here is the code:

https://sololearn.com/compiler-playground/WovfcT5q7ELF/?ref=app

Answer 1

There may be some browser compatibility issues, Windows 7 isn't supported anymore.
Check code compatibility here.

https://www.w3schools.com/cssref/css3_browsersupport.php

Answer 2

Web Developer AD Yes I think so.

Answer 3

What compatibility issues are you experiencing?

Answer 4

Lisa some lines of css code are not running neatly and in js nothing is working.
Do you think it is because of the old version of the windows and chrome?
I tried separating the css and js in different files and linking them but that also didn't work.

Answer 5

Thanks Chris Coder I saw that many were not supported on my version of chrome. But I have a question that if I deploy it using github pages then will all PCs using the latest version of chrome support it?