Sass is an extension of CSS, adding nested rules, variables, mixins, selector inheritance, and more. In Gatsby, Sass code can be translated to well-formatted, standard CSS using a plugin.
Install necessary NPM packages
Install the Emotion plugin in gatsby-config.js
Sweet, now it's ready to go.
Let's also write out an example stylesheet and page you can use to play with Sass.
Read more about Sass on the official Sass docs site: