How do I resize my code

Question

Hello fellow coders, I'm making a code that generates a qr code based on an input ( inspired by mitali ), the code is working, but the size is wrong, and I've tried many solutions, but it still won't work, if you know how to resize the code depending on the device's screen size, please leave a comment! ( Also if you know how to have zoom in and zoom out for the qr code that is controlled by the user please let me know! )
https://code.sololearn.com/WwUW3SJZ9U2G/?ref=app

Answer 1

https://code.sololearn.com/Wgik9T3pVbxD/?ref=app
https://code.sololearn.com/W8TD2J14e8MP/?ref=app

Answer 2

first you don't need width for your body
then set size for qr-code img
and if you want to change something for bigger(or smaller) screens use media queries

Answer 3

https://code.sololearn.com/W8Ss6BobXFde/?ref=app

Answer 4

Calviղ it doesn't work on my device