text: const withCss = require('@zeit/next-css');
  
  module.exports = withCss({
    webpack: (config, { isServer }) => {
      if (isServer) {
        const antStyles = /antd\/.*?\/style\/css.*?/;
        const origExternals = [...config.externals];
        config.externals = [
          (context, request, callback) => {
            if (request.match(antStyles)) return callback();
            if (typeof origExternals[0] === 'function') {
              origExternals[0](context, request, callback);
            } else {
              callback();
            }
          },
          ...(typeof origExternals[0] === 'function' ? [] : origExternals),
        ];
  
        config.module.rules.unshift({
          test: antStyles,
          use: 'null-loader',
        });
      }
      return config;
    },
  });
  