The Concrete CMS Composer-based installation includes Laravel Mix, which provides a nice API for defining Webpack build steps for your Laravel application using several common CSS and JavaScript pre-processors. With Laravel Mix, you have a file named webpack.mix.js in the root of your project, which contains simple JavaScript definitions for how you’d like to compile your SASS files into your resulting CSS files.
let mix = require('laravel-mix’);
mix.sass(‘resources/path/to/style.sass’, ‘public/application/css/style.css’);
With a configuration like this, compiling your SASS file into CSS can be done with the command
npm run prod