Optimizes CSS output

.browserslistrc

@@ -0,0 +1 @@
+last 2 Electron versions

package.json

@@ -11672,6 +11672,8 @@
 		"copy-webpack-plugin": "11.0.0",
 		"csp-html-webpack-plugin": "5.1.0",
 		"css-loader": "6.7.1",
+		"css-minimizer-webpack-plugin": "^4.0.0",
+		"cssnano-preset-advanced": "^5.3.8",
 		"esbuild": "0.15.5",
 		"esbuild-loader": "2.19.0",
 		"eslint": "8.22.0",

webpack.config.js

@@ -18,6 +18,7 @@ const path = require('path');
 const { validate } = require('schema-utils');
 const TerserPlugin = require('terser-webpack-plugin');
 const { WebpackError, webpack, optimize } = require('webpack');
+const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');
 const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
 
 module.exports =
@@ -391,6 +392,14 @@ function getWebviewsConfig(mode, env) {
 					deleteOriginalAssets: true,
 					generator: [imageGeneratorConfig],
 				}),
+				new CssMinimizerPlugin({
+					minimizerOptions: {
+						preset: [
+							'cssnano-preset-advanced',
+							{ discardUnused: false, mergeIdents: false, reduceIdents: false },
+						],
+					},
+				}),
 			],
 		},
 		module: {