Product Preview Card with flexbox and screenreader-only text

The worst thing I did when working on this challenge was forgetting to add screenreader-only text. I only realised how stupid I am when I watched Kevin Powell do this challenge!

Also, the solution for responsive images that I found in the MDN reference... didn't work no matter how hard I tried.

I guess my solution is not the most elegant one overall (the CSS code needs a lot more structure and some comments I think), but I'll submit this one and probably redo this challenge when I'm more experienced --- and then I'll compare the solutions and see how much I've grown. Hopefully.