marble/webpack.config.js

const path = require('path');
const ExtractTextPlugin = require('extract-text-webpack-plugin');

const extractSass = new ExtractTextPlugin({
  filename: 'marble.css'
});

module.exports = {
  entry: './main.js',
  output: {
    path: path.resolve(__dirname, 'build'),
    filename: 'bundle.js',
    publicPath: '/build'
  },
  module: {
    rules: [{
      test: /\.scss$/,
      use: extractSass.extract({
        use: [
          {
            loader: 'css-loader'
          },
          {
            loader: 'sass-loader',
            options: {
              includePaths: ['../../node_modules'],
              outputStyle: 'compressed'
            }
          }
        ]
      })
    }]
  },
  plugins: [
    extractSass
  ]
};