Product Preview Card Component using HTML and CSS (Sass)

What's the best way to compile Sass? Right now, I use the Live Sass Compiler extension in VSCode, which seems fine for personal development, but I don't know if it's good on a professional level.

Also, I was advised to use a post-processor for media queries (to flatten them all into one big media query, instead of being scattered around the file) but I have no idea how to go about that. Are there any good resources to learn about this? Just googling it didn't yield much help.