Why wont my create-react-app content center?

I used create-react-app and have been playing around with it. I understand the "app" class is supposed to center the content, and it did when I barely anything. But now it isn’t doing that. Can someone tell me where I’m going wrong?

App.js

import React from "react";
import './App.css';
import { Route, BrowserRouter as Router } from "react-router-dom";
import Home from "./pages/home";
import About from "./pages/about";
function App() {
  return (
    <div className="app">
    <Router>
        <Route path="/" exact component={Home} />
        <Route path="/about" exact component={About} />
    </Router> 
    </div>
  );
}

export default App;

about.js

import React from "react";
import { Button, Breadcrumb, Card } from "react-bootstrap"
import 'bootstrap/dist/css/bootstrap.min.css'

function About() {
    return (

        <div className="app">
            <h1>ABOUT PAGE</h1> 
            <a href="/">
            <img src="https://www.searchpng.com/wp-content/uploads/2019/02/Back-Arrow-Icon-PNG-715x715.png" height="50px" />
          </a> 
          <Card className="mb-3" style={{ color: "#000"}}>
              <Card.Img/>
              <Card.Body>
              <Card.Title>
                  Card Example
              </Card.Title>  
              <Card.Text>
                  This is an example of react bootstrap cards
              </Card.Text>
              </Card.Body>
          </Card>
          <Breadcrumb>
          <Breadcrumb.Item>Test</Breadcrumb.Item>
          <Breadcrumb.Item>Test 2</Breadcrumb.Item>
          <Breadcrumb.Item>Test 3</Breadcrumb.Item>
          </Breadcrumb>
          <Button variant="success">Test Button</Button>
        </div>

    )
}

export default About;

5 thoughts on “Why wont my create-react-app content center?”

  1. 949069 52708Hey. Neat post. There is a difficulty with your site in firefox, and you might want to check this The browser may be the market chief and a large component of other folks will omit your outstanding writing because of this dilemma. 212820

    Reply
  2. I think that what you published made a bunch of sense.
    However, consider this, suppose you added a little information? I
    am not saying your content is not good., however
    what if you added something that makes people want more?

    I mean Why wont my create-react-app content center? – JavaScript Help is kinda boring.
    You might peek at Yahoo’s home page and watch how they
    write article headlines to get viewers to open the links.
    You might try adding a video or a pic or two to grab readers interested about what you’ve written. In my opinion,
    it might make your website a little livelier.

    Reply