this is my webpack configuration

const path = require("path")
const CleanWebpackPlugin = require("clean-webpack-plugin")
const HtmlWebpackPlugin = require("html-webpack-plugin")
const pkg = require("../package.json")
const webpack = require("webpack")
const BundleAnalyzerPlugin = require("webpack-bundle-analyzer").BundleAnalyzerPlugin

module.exports = {
  context: path.resolve(__dirname, "../"),
  mode: "development",
  target: "web",
  entry: {
    app: "./src/main.js"
  },
  output: {
    filename: "js/[name].bundle.js",
    path: path.resolve("./dist"),
    publicPath: "/"
  },
  resolve: {
    // modules: [
    //   path.resolve("./src"),
    //   "node_modules"
    // ],
    alias: {
      "@": path.resolve("./src")
    },
    extensions: [".js", ".vue", ".json"]
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        include: [path.resolve("./src")],
        loader: "babel-loader"
      },
      {
        test: /\.js$/,
        include: [path.resolve("./src")],
        enforce: "pre",
        loader: "eslint-loader",
        options: {
          formatter: require("eslint-friendly-formatter"),
          emitError: true
        }
      },
      {
        test: /\.css$/,
        use: [
          {
            loader: "style-loader",
            options: {
              sourceMap: true
            }
          },
          {
            loader: "css-loader",
            options: {
              sourceMap: true,
              importLoaders: 1
            }
          },
          {
            loader: "postcss-loader",
            options: {
              sourceMap: true
            }
          }
        ]
      },
      {
        test: /\.(png|jpe?g|gif|svg)$/,
        loader: "url-loader",
        options: {
          limit: 8192,
          name: "images/[name].[hash:5].[ext]"
        }
      },
      {
        test: /\.(woff2?|eot|ttf|otf)(\?.*)?$/,
        loader: "url-loader",
        options: {
          limit: 10240,
          name: "fonts/[name].[hash:5].[ext]"
        }
      }
    ]
  },
  devServer: {
    contentBase: path.resolve("static"),
    publicPath: "/",
    compress: true,
    hot: true,
    open: true,
    overlay: true,
    port: 9999,
    clientLogLevel: "warning",
    proxy: {}
  },
  plugins: [
    new CleanWebpackPlugin([path.resolve("./dist")], {
      root: path.resolve("./")
    }),
    new HtmlWebpackPlugin({
      title: pkg.name,
      filename: "index.html",
      template: path.resolve("index.html")
    }),
    new webpack.HotModuleReplacementPlugin(),
    new BundleAnalyzerPlugin()
  ],
  devtool: "cheap-eval-source-map"
}

Why did you type in style-loader and css-loader when using analyzer to analyze after packaging? Causes the file to be very large

"webpack": "^4.12.2",
"webpack-cli": "^3.0.8"

package.json

{
  "name": "bundletask",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "webpack --display --config ./build/webpack.config.js",
    "dev": "webpack-dev-server --inline --progress --color --config ./build/webpack.config.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "autoprefixer": "^8.6.4",
    "babel-core": "^6.26.3",
    "babel-eslint": "^8.2.5",
    "babel-loader": "^7.1.4",
    "babel-plugin-transform-runtime": "^6.23.0",
    "babel-preset-env": "^1.7.0",
    "babel-preset-stage-2": "^6.24.1",
    "chalk": "^2.4.1",
    "clean-webpack-plugin": "^0.1.19",
    "css-loader": "^0.28.11",
    "eslint": "^5.0.1",
    "eslint-config-standard": "^11.0.0",
    "eslint-friendly-formatter": "^4.0.1",
    "eslint-loader": "^2.0.0",
    "eslint-plugin-import": "^2.13.0",
    "eslint-plugin-node": "^6.0.1",
    "eslint-plugin-promise": "^3.8.0",
    "eslint-plugin-standard": "^3.1.0",
    "file-loader": "^1.1.11",
    "html-webpack-plugin": "^3.2.0",
    "postcss-loader": "^2.1.5",
    "style-loader": "^0.21.0",
    "url-loader": "^1.0.1",
    "webpack": "^4.12.2",
    "webpack-bundle-analyzer": "^2.13.1",
    "webpack-cli": "^3.0.8",
    "webpack-dev-server": "^3.1.4"
  }
}