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                <button id="start">開始</button>
<div class="animation-area">
  <img id="image" src="" width="50" height="50" alt="site-logo">


                .animation-area {
  margin-top: 1rem;


                const start = document.getElementById('start'); // 開始ボタン
const image = document.getElementById('image'); // ロゴ画像

// スタートボタンをクリックしたら
start.addEventListener('click', () => {
  // 画像を左端から200px右に動かす
    // 途中の状態を表す配列
      { transform: 'translateX(0)'}, // 開始時の状態(左端)
      { transform: 'translateX(200px)' } // 終了時の状態(左端から200pxの位置)
    // タイミングに関する設定
      fill: 'backwards', // 再生前後の状態(再生前、開始時の状態を適用)
      duration: 1000, // 再生時間(1000ミリ秒)