next.config.js

const prod = process.env.NODE_ENV === "production";
const withBundleAnalyzer = require("@zeit/next-bundle-analyzer");
const { BundleAnalyzerPlugin } = require("webpack-bundle-analyzer");
const withCSS = require('@zeit/next-css')

module.exports = withCSS({
  analyzeServer: ["server", "both"].includes(process.env.BUNDLE_ANALYZE),
  analyzeBrowser: ["browser", "both"].includes(process.env.BUNDLE_ANALYZE),
  bundleAnalyzerConfig: {
    server: {
      analyzerMode: 'static',
      reportFilename: '../../bundles/server.html'
    },
    browser: {
      analyzerMode: 'static',
      reportFilename: '../bundles/client.html'
    }
  },
  serverRuntimeConfig: {
    // Will only be available on the server side
    mySecret: "secret"
  },
  publicRuntimeConfig: {
    // Will be available on both server and client
    backendUrl: prod ? "https://rest.urteile-gesetze.de" : "http://localhost:8090",
    logging: prod ? "info" : "debug"
  }

});