webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        exclude: /node_modules/,
        loader: 'babel-loader'
      },
      {
        test: /\.scss$/,
        use: [
            "style-loader",
            "css-loader",
            "sass-loader"
        ]
      },
      {
        test: /\.css$/,
        use: [
            "style-loader",
            "css-loader"
        ]
      }
    ]
  }
}