我是编码新手，所以我正在遵循本教程：https://www.sitepoint.com/react-tutorial-build-calculator-app/ 我无法渲染任何元素。这是运行网络应用程序时控制台显示的内容

这是我的 App.js 代码：

import Wrapper from "./components/Wrapper.js";
import Screen from "./components/Screen.js";
import ButtonBox from "./components/ButtonBox.js";
import Button from "./components/Button.js";

const btnValues = [
  ["C", "+-", "%", "/"],
  [7, 8, 9, "X"],
  [4, 5, 6, "-"],
  [1, 2, 3, "+"],
  [0, ".", "="],
];

const App = () => {
  return (
    <Wrapper>
      <Screen value="0" />
      <ButtonBox>
        {
          btnValues.flat().map((btn, i) => {
            return (
              <Button
                key={i}
                className={btn === "=" ? "equals" : ""}
                value={btn}
                onClick={() => {
                  console.log(`${btn} clicked!`);
                }}
              />
            );
          })
        }
      </ButtonBox>
    </Wrapper>
  );
};

export default App;

然后这是index.js：

import React from 'react';
import ReactDOM from 'react-dom/client';

import './index.css';
import App from './App';

ReactDOM.render(
  <React.StrictMode>
    <App />
  </React.StrictMode>,
  document.getElementById("root")
);