Order summary component

Hi! I hope all of you are very well.

I was doing initial level exercises to consolidate my knowledge in html and css, and these helped me to realize that there are things that I am still not very clear about, I hope you can help me.

Regarding the html document, I was very satisfied with how I did it, but surely you can make me notice something to improve.

With respect to css, my main problem is that when I have to tackle an exercise of this type, I don't know whether to give the article static measurements or make it flexible so that it takes shape as I add margins to each of its children(as I did in this case).

Another thing I would like to know is if responsive text is necessary in every exercise (using clamp(1rem, 0.75rem + 1.5vw,2rem) )

(I had a huge headache defining the font-size of the :root with a clamp())

Thank you and I hope I have not made you dizzy, I am trying to identify my biggest difficulty