try the below code in your webpack to add a wrapper class for all classes present in your project.

module: {
 rules: [
      {
        test: /\.(css|less)$/i,
        use: [
          {
            loader: "style-loader",
          },
          {
            loader: "css-loader",
          },
          {
            loader: "postcss-loader",
            options: {
              postcssOptions: {
                plugins: {
                  "postcss-increase-specificity": {
                    stackableRoot: `.container`,
                    repeat: 1,
                  },
                },
              },
            },
          },
          {
            loader: "less-loader",
            options: {
              lessOptions: {
                javascriptEnabled: true,
              },
            },
          },
        ],
      },
    ],
  }