Product review card using CSS SASS

This is the very first challenge that I deal with, so I was totally confused at the beginning and got messed up from assigning variables to selecting html tag while building the project. I was trying to get the product looking as close to the design as possible.

• I am not sure of the area of responsive code, since the requested widths between the two view modes are different significantly. Should I myself choose a larger width for responsiveness between mobile and desktop views?
• I chose to override the default font size of the browser with the requested font size. Is it a good choice?
• Mobile-first or desktop-first workflow? which one is a better approach for the most part?