https://www.shopify.com/nz/partners/blog/a-beginners-guide-to-sass-with-shopify-part-2-making-stylesheets-smarter-with-sass-mixins-and-functions
Learn about Sass functions and mixins, and get some great examples of how to use them in Shopify theme development.
guidesassshopifyptmixins
https://gerillass.com/
Gerillass is an open-source Sass library with a set of Sass mixins and functions to help frontend developers build modern websites quickly.
modern web designsass mixinsbestlibrary