text: let game =  {
      words: [
          'uma',
          'omaturi',
          'iruka',
          'ootoro',
          'iyasikei',
          'sutoraiku',
          'oosouji',
          'a-telisuto',
      ],
      //↓kana
      hurigana: [
          'ウマ',
          'お祭り',
          'イルカ',
          '大トロ',
          '癒し系',
          'ストライク',
          '大掃除',
          'アーティスト',
      ],
  
      currentWord: '',
      //↓currentWordのふりがなver
      currentHurigana: '',
  
      matchedIndex: 0,
      startTime: null,
      isPlaying: false,
      mainArea: document.getElementById('main'),
      resultArea: document.getElementById('result'),
      huriganaArea: document.getElementById('kana'),
  
      start: function(){
          game.isPlaying = true;
          game.startTime = Date.now();
          //
          game.setWord();
          //
          game.setHurigana();
      },
  
      setWord: function(){
          game.currentWord = game.words.shift() || '';
          game.matchedIndex = 0;
          game.displayWord();
      },
  
      displayWord: function(){
          game.mainArea.innerText = '_'.repeat(game.matchedIndex) + game.currentWord.substring(game.matchedIndex);
      },
  
      //↓setWordのふりがなver
      setHurigana: function(){
          game.currentHurigana = game.hurigana.shift() || '';
          game.displayHurigana();
      },
      
      displayHurigana: function(){
          game.huriganaArea.innerText = '_'.repeat(game.matchedIndex) + game.currentHurigana.substring(game.matchedIndex);
      },
  
      // 追加 ----------------------
      isFinished: function(){
          return game.words.length === 0;
      },
  
      displayResult: function(){
          const currentTime = Date.now();
          const elapsedTime = formattedSeconds(currentTime - game.startTime);
          game.resultArea.innerText = `${elapsedTime} 秒かかりました。\n もう一度プレイする場合にはブラウザをリロードしてください。`;
          game.isPlaying = false;
      },
      // ---------------------------
  };
  
  // 追加 --------------------------
  document.onclick = () => {
      if (game.isPlaying === false){
          game.start();
      }
  };
  // -------------------------------
  
  // 追加 ---------------------------
  document.onkeydown = (event) => {
      if (event.key !== game.currentWord[game.matchedIndex]){
          return;
      }
  
      game.matchedIndex++;
      game.displayWord();
  
      if (game.matchedIndex === game.currentWord.length){
          if (game.isFinished()){
              game.displayResult();
          };
          game.setWord();
          game.setHurigana();
      }
  };
  // -------------------------------
  
  // 追加 ---------------------------
  //utils
  function formattedSeconds(ms){
      return (ms / 1000).toFixed(2);
  }
  // --------------------------------