Reactチュートリアル+Material-UI

こちらの続きです。
React クラスコンポーネント propsの型指定2 - C#ATIA

こちらを取り組みました。
チュートリアル：React の導入 – React

素の状態だとチュートリアルと見た目が違う・・・。
恐らくCSSだろうとは思うのですが。(画像左)

折角なのでMaterial-UIを利用したのが右側です。

import React from 'react';
import { BrowserRouter as Router, Switch, Route } from 'react-router-dom';
import CssBaseline from '@material-ui/core/CssBaseline';
import Card from '@material-ui/core/Card';
import CardContent from '@material-ui/core/CardContent';
import Button from '@material-ui/core/Button';

function Square(props) {
  return (
    <Button
      className="square"
      variant="contained"
      color="primary"
      onClick={props.onClick}
    >
      {props.value}
    </Button>
  );
}

class Board extends React.Component {
  renderSquare(i) {
    return (
      <Square
        value={this.props.squares[i]}
        onClick={() => this.props.onClick(i)}
      />
    );
  }

  render() {
    return (
      <div>
        <div className="board-row">
          {this.renderSquare(0)}
          {this.renderSquare(1)}
          {this.renderSquare(2)}
        </div>
        <div className="board-row">
          {this.renderSquare(3)}
          {this.renderSquare(4)}
          {this.renderSquare(5)}
        </div>
        <div className="board-row">
          {this.renderSquare(6)}
          {this.renderSquare(7)}
          {this.renderSquare(8)}
        </div>
      </div>
    );
  }
}

class Game extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      history: [
        {
          squares: Array(9).fill(null),
        },
      ],
      stepNumber: 0,
      xIsNext: true,
    };
  }

  handleClick(i) {
    const history = this.state.history.slice(0, this.state.stepNumber + 1);
    const current = history[history.length - 1];
    const squares = current.squares.slice();
    if (calculateWinner(squares) || squares[i]) {
      return;
    }
    squares[i] = this.state.xIsNext ? 'X' : 'O';
    this.setState({
      history: history.concat([
        {
          squares: squares,
        },
      ]),
      stepNumber: history.length,
      xIsNext: !this.state.xIsNext,
    });
  }

  jumpTo(step) {
    this.setState({
      stepNumber: step,
      xIsNext: step % 2 === 0,
    });
  }

  render() {
    const history = this.state.history;
    const current = history[this.state.stepNumber];
    const winner = calculateWinner(current.squares);
    const moves = history.map((step, move) => {
      const desc = move ? 'Go to move #' + move : 'Go to game start';
      return (
        <li key={move}>
          <Button
            variant="contained"
            color="secondary"
            onClick={() => this.jumpTo(move)}
          >
            {desc}
          </Button>
        </li>
      );
    });

    let status;
    if (winner) {
      status = 'Winner: ' + winner;
    } else {
      status = 'Next player: ' + (this.state.xIsNext ? 'X' : 'O');
    }

    return (
      <div className="game">
        <div className="game-board">
          <Board
            squares={current.squares}
            onClick={(i) => this.handleClick(i)}
          />
        </div>
        <CssBaseline />
        <div className="game-info">
          <Card>
            <CardContent>{status}</CardContent>
          </Card>
          <ol>{moves}</ol>
        </div>
      </div>
    );
  }
}

function calculateWinner(squares) {
  const lines = [
    [0, 1, 2],
    [3, 4, 5],
    [6, 7, 8],
    [0, 3, 6],
    [1, 4, 7],
    [2, 5, 8],
    [0, 4, 8],
    [2, 4, 6],
  ];
  for (let i = 0; i < lines.length; i++) {
    const [a, b, c] = lines[i];
    if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
      return squares[a];
    }
  }
  return null;
}

export default function App() {
  return (
    <Router>
      <Switch>
        <Route path="/" component={Game} />
      </Switch>
    </Router>
  );
}

テーマの利用の仕方がイマイチわからないなぁ。