# Pre-Processing CSS

CSS pre-processors like Sass, SCSS, Less and Stylus are still popular today, so it's natual that Poi supports them out of the box. However relevant dependencies for transpilation are required, be sure to follow the installation instructions below.

# Sass / SCSS

yarn add sass-loader node-sass --dev

Then you can import .scss and .sass files. If you want to import files from node_modules, make sure to add ~ prefix as follows:

// importing a css file from the nprogress node module
@import '~nprogress/nprogress'; 

# Less

yarn add less-loader less --dev

# Stylus

yarn add stylus-loader stylus --dev

# Passing Options to Pre-Processor Loaders

Sometimes you may want to pass options to the pre-processor's webpack loader. You can do that using the css.loaderOptions option in poi.config.js. For example, to pass some shared global variables to all your Sass styles:

// poi.config.js
module.exports = {
  css: {
    loaderOptions: {
      // pass options to sass-loader
      sass: {
        // @/ is an alias to src/
        // so this assumes you have a file named `src/variables.scss`
        data: `@import "@/variables.scss";`
      }
    }
  }
}