Responsive Mobile-First Social Proof Page

Making this responsive took a lot more thought that I expected. I struggled with the layout of the comment cards and the ratings quite a bit. After a lot of trial and error I managed to figure out using grid and flex together can work. Still not entirely sure how technically correct this is, but it seems like it works! The responsiveness isn't flawless, but a priority goal was to prevent any overlap of elements on the webpage.

The HTML and CSS checked out valid (I need to remember accessibility and add the alt="" to the images...) but I would really like to know if I used flex and grid in an efficient way. How can I use them better?