How to make a fixed column in Bootstrap?

Question

css

Greetings!
There is a column in which row is nested and there are three more columns
in it. I need to make these three columns fixed, but when I set them to position: fixed , they begin to be positioned not relative to their parent, but relative to the entire browser window, why is that? and how can i avoid it?
Thanks in advance !

Answer 1

I prescribe position: fixed then they begin to be positioned not relative to their parent, but relative to the entire browser window, why is that?

Because specification.
https://webref.ru/css/position
Conclusion: do not use position: fixed
Use absolute and relative to the parent.