Mobile-first interactive rating component built w/ VanillaJS

Question: I wrote all the CSS for mobile first, and then wrapped the styles for the desktop view in a media query — is that a good workflow? Keen to learn best practices.

Other notes:

• Written with basic JS, though I look forward to learning React soon.
• This might be the most CSS I've ever written by myself and without a framework. The project helped me to grok Flexbox, which was great.
• I struggled pretty hard before adding a CSS Reset stylesheet to my project - gamechanger, won't forget to do that again!