diff --git "a/index.html" "b/index.html"
--- "a/index.html"
+++ "b/index.html"
@@ -1,14 +1,17 @@
 <!DOCTYPE html>
 <html lang="ja">
+
 <head>
     <meta charset="UTF-8">
-    <script src="https://soiz1-eruda3.hf.space/eruda.js"></script><script>eruda.init();</script>
-    <link rel="icon" type="image/svg+xml" href='data:image/svg+xml;base64,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' />
-
+    <script src="https://soiz1-eruda3.hf.space/eruda.js"></script>
+    <script>
+    eruda.init();
+    </script>
+    <link rel="icon" type="image/svg+xml" href="data:image/svg+xml;base64,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">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>高度な音声動画プレイヤー</title>
     <style>
-        /* テクノロジー風背景スタイル */
+    /* テクノロジー風背景スタイル */
         .tech-background {
             position: fixed;
             top: 0;
@@ -759,188 +762,220 @@
         }
     </style>
 </head>
+
 <body>
-<script>
-// 動画パスを再設定
-document.addEventListener('DOMContentLoaded', function() {
-    const urlParams = new URLSearchParams(window.location.search);
-    const isTMode = urlParams.has('mode') && urlParams.get('mode') === 't';
-    const videoSource = document.querySelector('#video source');
-    
-    if (isTMode && videoSource) {
-        videoSource.src = '/t/v.mp4';
-        const video = document.getElementById('video');
-        video.load();
-    }
-});
-</script>
+    <script>
+    // 動画パスを再設定
+    document.addEventListener('DOMContentLoaded', function() {
+        const urlParams = new URLSearchParams(window.location.search);
+        const isTMode = urlParams.has('mode') && urlParams.get('mode') === 't';
+        const videoSource = document.querySelector('#video source');
+        
+        if (isTMode && videoSource) {
+            videoSource.src = '/t/v.mp4';
+            const video = document.getElementById('video');
+            video.load();
+        }
+    });
+    </script>
     <!-- テクノロジー風背景 -->
-    <div class="tech-background" id="techBg"></div>
-    
+    <div class="tech-background" id="techBg">
+    </div>
     <!-- ローディングオーバーレイ -->
     <div class="loading-overlay" id="loadingOverlay">
         <div class="spinner-box">
-            <div class="blue-orbit leo"></div>
-            <div class="green-orbit leo"></div>
-            <div class="red-orbit leo"></div>
-            <div class="white-orbit w1 leo"></div>
-            <div class="white-orbit w2 leo"></div>
-            <div class="white-orbit w3 leo"></div>
+            <div class="blue-orbit leo">
+            </div>
+            <div class="green-orbit leo">
+            </div>
+            <div class="red-orbit leo">
+            </div>
+            <div class="white-orbit w1 leo">
+            </div>
+            <div class="white-orbit w2 leo">
+            </div>
+            <div class="white-orbit w3 leo">
+            </div>
         </div>
     </div>
-    
     <h1>高度な音声動画プレイヤー</h1>
     <div class="settings">
-      
-    <h2>サービスワーカー設定</h2>
-      <div class="setting-item">
-        <label><input type="checkbox" id="sw-video" checked> 動画ファイル (/v.mp4)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-t-video" checked> 動画ファイル (/t/v.mp4)</label>
-    </div><br>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-piano" checked> ピアノ音声 (/p.mp3)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-soprano" checked> ソプラノ音声 (/s.mp3)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-alto" checked> アルト音声 (/a.mp3)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-tenor" checked> テノール音声 (/t.mp3)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-combined" checked> 全体音声 (/k.mp3)</label>
-    </div><br>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-t-piano" checked> ピアノ音声 (/t/p.mp3)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-t-soprano" checked> ソプラノ音声 (/t/s.mp3)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-t-alto" checked> アルト音声 (/t/a.mp3)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-t-tenor" checked> テノール音声 (/t/t.mp3)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-t-combined" checked> 全体音声 (/t/k.mp3)</label>
-    </div><br>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-index" checked> インデックスファイル (/index.html)</label>
-    </div>
-    <div class="setting-item">
-        <label><input type="checkbox" id="sw-root" checked> ルートファイル (/)</label>
-    </div>
-    <a>絶対に押さないでください。これはオフラインでも使用できるようにする機能のテスト中で、ページが更新できなくなります。</a><br>
-    <button class="combine-button" id="sw-register-btn">登録を開始</button>
-    <div class="combine-status" id="sw-status"></div>
-      <script>
-document.getElementById('sw-register-btn').addEventListener('click', async () => {
-  const statusElem = document.getElementById('sw-status');
-
-  function updateStatus(message) {
-    console.log(message);
-    statusElem.textContent = message;
-  }
-
-  function updateError(message, error) {
-    const errorMsg = `${message}\nエラー詳細: ${error?.message || error}`;
-    console.error(errorMsg, error);
-    statusElem.textContent = errorMsg;
-  }
-
-  if (!('serviceWorker' in navigator)) {
-    updateError('このブラウザはService Workerに対応していません。');
-    return;
-  }
-
-  try {
-    updateStatus('既存のService Workerをアンレジスター中...');
-
-    const registrations = await navigator.serviceWorker.getRegistrations();
-    for (const registration of registrations) {
-      try {
-        await registration.unregister();
-        updateStatus('Service Workerをアンレジスターしました。');
-      } catch (unregErr) {
-        updateError('Service Workerのアンレジスター中に例外が発生しました。', unregErr);
+        <h2>サービスワーカー設定</h2>
+        <div hidden><!--邪魔だから一時的に非表示-->
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-video" checked>動画ファイル (/v.mp4)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-t-video" checked>動画ファイル (/t/v.mp4)</label>
+        </div>
+        <br>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-piano" checked>ピアノ音声 (/p.mp3)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-soprano" checked>ソプラノ音声 (/s.mp3)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-alto" checked>アルト音声 (/a.mp3)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-tenor" checked>テノール音声 (/t.mp3)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-combined" checked>全体音声 (/k.mp3)</label>
+        </div>
+        <br>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-t-piano" checked>ピアノ音声 (/t/p.mp3)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-t-soprano" checked>ソプラノ音声 (/t/s.mp3)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-t-alto" checked>アルト音声 (/t/a.mp3)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-t-tenor" checked>テノール音声 (/t/t.mp3)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-t-combined" checked>全体音声 (/t/k.mp3)</label>
+        </div>
+        <br>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-index" checked>インデックスファイル (/index.html)</label>
+        </div>
+        <div class="setting-item">
+            <label>
+                <input type="checkbox" id="sw-root" checked>ルートファイル (/)</label>
+        </div>
+        </div>
+        <a>絶対に押さないでください。これはオフラインでも使用できるようにする機能のテスト中で、ページが更新できなくなります。</a>
+        <br>
+        <button class="combine-button" id="sw-register-btn">登録を開始</button>
+        <div class="combine-status" id="sw-status">
+        </div>
+        <script>
+    document.getElementById('sw-register-btn').addEventListener('click', async () => {
+      const statusElem = document.getElementById('sw-status');
+    
+      function updateStatus(message) {
+        console.log(message);
+        statusElem.textContent = message;
+      }
+    
+      function updateError(message, error) {
+        const errorMsg = `${message}\nエラー詳細: ${error?.message || error}`;
+        console.error(errorMsg, error);
+        statusElem.textContent = errorMsg;
+      }
+    
+      if (!('serviceWorker' in navigator)) {
+        updateError('このブラウザはService Workerに対応していません。');
         return;
       }
-    }
-
-    updateStatus('アンレジスター完了。新しいService Workerを登録中...');
-
-    setTimeout(async () => {
+    
       try {
-        const newRegistration = await navigator.serviceWorker.register('/sw.js');
-        updateStatus('Service Workerが正常に登録されました。\n登録範囲: ' + newRegistration.scope);
-
-        // チェックボックスの状態からファイルリストを作成
-        const fileMap = {
-          'sw-video': '/v.mp4',
-          'sw-t-video': '/t/v.mp4',
-          'sw-piano': '/p.mp3',
-          'sw-soprano': '/s.mp3',
-          'sw-alto': '/a.mp3',
-          'sw-tenor': '/t.mp3',
-          'sw-combined': '/k.mp3',
-          'sw-t-piano': '/t/p.mp3',
-          'sw-t-soprano': '/t/s.mp3',
-          'sw-t-alto': '/t/a.mp3',
-          'sw-t-tenor': '/t/t.mp3',
-          'sw-t-combined': '/t/k.mp3',
-          'sw-index': '/index.html',
-          'sw-root': '/',
-        };
-
-        // チェックされているものだけ抽出
-        const filesToCache = [];
-        const checkboxStates = {};
-        for (const [id, url] of Object.entries(fileMap)) {
-          const checkbox = document.getElementById(id);
-          if (!checkbox) continue;
-          checkboxStates[id] = checkbox.checked;
-          if (checkbox.checked) {
-            filesToCache.push(url);
+        updateStatus('既存のService Workerをアンレジスター中...');
+    
+        const registrations = await navigator.serviceWorker.getRegistrations();
+        for (const registration of registrations) {
+          try {
+            await registration.unregister();
+            updateStatus('Service Workerをアンレジスターしました。');
+          } catch (unregErr) {
+            updateError('Service Workerのアンレジスター中に例外が発生しました。', unregErr);
+            return;
           }
         }
-
-        // SWがコントロール中ならメッセージ送信
-        if (navigator.serviceWorker.controller) {
-          navigator.serviceWorker.controller.postMessage({
-            type: 'CACHE_FILES',
-            files: filesToCache,
-            checkboxStates: checkboxStates,
-          });
-          updateStatus('キャッシュ更新のメッセージをサービスワーカーに送信しました。');
-        } else {
-          updateStatus('サービスワーカーがコントロール中ではありません。キャッシュ更新メッセージは送信できません。');
-        }
-      } catch (regErr) {
-        updateError('Service Workerの登録に失敗しました。', regErr);
+    
+        updateStatus('アンレジスター完了。新しいService Workerを登録中...');
+    
+        setTimeout(async () => {
+          try {
+            const newRegistration = await navigator.serviceWorker.register('/sw.js');
+            updateStatus('Service Workerが正常に登録されました。\n登録範囲: ' + newRegistration.scope);
+    
+            // チェックボックスの状態からファイルリストを作成
+            const fileMap = {
+              'sw-video': '/v.mp4',
+              'sw-t-video': '/t/v.mp4',
+              'sw-piano': '/p.mp3',
+              'sw-soprano': '/s.mp3',
+              'sw-alto': '/a.mp3',
+              'sw-tenor': '/t.mp3',
+              'sw-combined': '/k.mp3',
+              'sw-t-piano': '/t/p.mp3',
+              'sw-t-soprano': '/t/s.mp3',
+              'sw-t-alto': '/t/a.mp3',
+              'sw-t-tenor': '/t/t.mp3',
+              'sw-t-combined': '/t/k.mp3',
+              'sw-index': '/index.html',
+              'sw-root': '/',
+            };
+    
+            // チェックされているものだけ抽出
+            const filesToCache = [];
+            const checkboxStates = {};
+            for (const [id, url] of Object.entries(fileMap)) {
+              const checkbox = document.getElementById(id);
+              if (!checkbox) continue;
+              checkboxStates[id] = checkbox.checked;
+              if (checkbox.checked) {
+                filesToCache.push(url);
+              }
+            }
+    
+            // SWがコントロール中ならメッセージ送信
+            if (navigator.serviceWorker.controller) {
+              navigator.serviceWorker.controller.postMessage({
+                type: 'CACHE_FILES',
+                files: filesToCache,
+                checkboxStates: checkboxStates,
+              });
+              updateStatus('キャッシュ更新のメッセージをサービスワーカーに送信しました。');
+            } else {
+              updateStatus('サービスワーカーがコントロール中ではありません。キャッシュ更新メッセージは送信できません。');
+            }
+          } catch (regErr) {
+            updateError('Service Workerの登録に失敗しました。', regErr);
+          }
+        }, 500);
+      } catch (err) {
+        updateError('Service Workerの処理中に致命的なエラーが発生しました。', err);
       }
-    }, 500);
-  } catch (err) {
-    updateError('Service Workerの処理中に致命的なエラーが発生しました。', err);
-  }
-});
-      </script>
-</div>
+    });
+        </script>
+    </div>
     <div class="container">
         <div class="video-container" id="video-container">
             <!-- バッファリングインジケーター -->
-            <div id="buffering-indicator"><div class="loader"></div></div>
+            <div id="buffering-indicator">
+                <div class="loader">
+                </div>
+            </div>
             <!-- 同期ステータス -->
             <div class="sync-status" id="sync-status">
-                <span id="sync-status-text"></span>
+                <span id="sync-status-text">
+                </span>
                 <button id="sync-status-close">×</button>
             </div>
             <script src="https://unpkg.com/draggabilly@2/dist/draggabilly.pkgd.min.js"></script>
-            <script>new Draggabilly('#sync-status');</script>
+            <script>
+    new Draggabilly('#sync-status');
+            </script>
             <!-- 無効状態のオーバーレイ -->
             <div class="disabled-overlay" id="disabledOverlay">
                 <div class="disabled-message">
@@ -948,16 +983,19 @@ document.getElementById('sw-register-btn').addEventListener('click', async () =>
                     <p>下の音声コントロールで各パートの音量を調整し、「合成」ボタンを押してください</p>
                 </div>
             </div>
-            
             <video id="video" muted>
-                <source src="v.mp4" type="video/mp4" allowPictureInPicture>
+                <source src="v.mp4" type="video/mp4" allowpictureinpicture>
+                </source>
             </video>
             <div class="video-controls">
                 <div class="progress-container" id="progress-container">
-                    <div class="progress-bar" id="progress-bar"></div>
+                    <div class="progress-bar" id="progress-bar">
+                    </div>
                     <div class="progress-time" id="progress-time">00:00</div>
-                    <div class="progress-marker" id="start-marker" style="left: 0%; display: none;"></div>
-                    <div class="progress-marker" id="end-marker" style="left: 100%; display: none;"></div>
+                    <div class="progress-marker" id="start-marker" style="left: 0%; display: none;">
+                    </div>
+                    <div class="progress-marker" id="end-marker" style="left: 100%; display: none;">
+                    </div>
                 </div>
                 <div class="main-controls">
                     <button class="control-button" id="play-pause-btn" disabled>▶</button>
@@ -974,30 +1012,27 @@ document.getElementById('sw-register-btn').addEventListener('click', async () =>
                 </div>
             </div>
         </div>
-        
-        <div class="tech-decoration"></div>
-        
-        <div class="settings">
-        <div class="time-markers-container" id="time-markers-container">
-            <!-- ここにタイムマーカーが動的に追加されます -->
+        <div class="tech-decoration">
         </div>
-        
-        <div class="setting-item">
-            <label for="start-time">再生開始秒数:</label>
-            <div class="time-input-container">
-                <input type="number" id="start-time" min="0" value="0" step="0.01" disabled>
-                <button class="time-set-button" id="set-start-time" disabled>現在の秒数に設定</button>
+        <div class="settings">
+            <div class="time-markers-container" id="time-markers-container">
+                <!-- ここにタイムマーカーが動的に追加されます -->
             </div>
-        </div>
-        
-        <div class="setting-item">
-            <label for="end-time">再生終了秒数:</label>
-            <div class="time-input-container">
-                <input type="number" id="end-time" min="0" value="0" step="0.01" disabled>
-                <button class="time-set-button" id="set-end-time" disabled>現在の秒数に設定</button>
-                <button class="time-set-button" id="reset-end-time" disabled>動画の長さに戻す</button>
+            <div class="setting-item">
+                <label for="start-time">再生開始秒数:</label>
+                <div class="time-input-container">
+                    <input type="number" id="start-time" min="0" value="0" step="0.01" disabled>
+                    <button class="time-set-button" id="set-start-time" disabled>現在の秒数に設定</button>
+                </div>
+            </div>
+            <div class="setting-item">
+                <label for="end-time">再生終了秒数:</label>
+                <div class="time-input-container">
+                    <input type="number" id="end-time" min="0" value="0" step="0.01" disabled>
+                    <button class="time-set-button" id="set-end-time" disabled>現在の秒数に設定</button>
+                    <button class="time-set-button" id="reset-end-time" disabled>動画の長さに戻す</button>
+                </div>
             </div>
-        </div>
             <h2>設定</h2>
             <div class="setting-item">
                 <label for="start-time">再生開始秒数:</label>
@@ -1038,9 +1073,8 @@ document.getElementById('sw-register-btn').addEventListener('click', async () =>
                 </div>
             </div>
         </div>
-        
-        <div class="tech-decoration"></div>
-        
+        <div class="tech-decoration">
+        </div>
         <div class="audio-controls">
             <h2>音声コントロール</h2>
             <div class="audio-item">
@@ -1068,12 +1102,11 @@ document.getElementById('sw-register-btn').addEventListener('click', async () =>
                 <input type="range" class="audio-slider" data-audio="k" min="0" max="1" step="0.01" value="0">
                 <span class="slider-value volume-value">0.00</span>
             </div>
-
             <!-- 合成ボタンとステータス -->
             <button class="combine-button" id="combine-button">音声を合成</button>
-            <div class="combine-status" id="combine-status"></div>
+            <div class="combine-status" id="combine-status">
+            </div>
         </div>
-
         <!-- プレビューセクション -->
         <div class="preview-section" id="preview-section">
             <h3 hidden>プレビュー</h3>
@@ -1082,1219 +1115,1218 @@ document.getElementById('sw-register-btn').addEventListener('click', async () =>
             <span id="preview-time" hidden>00:00 / 00:00</span>
         </div>
     </div>
-    
     <!-- 全画面時のロックボタン -->
     <button class="lock-controls-btn" id="lock-controls-btn" title="コントロールバーを固定">🔒</button>
+    <script>
+    document.addEventListener('DOMContentLoaded', function() {
+        // 同期管理用の変数
+        let lastSyncTime = 0;
+        let isBuffering = false;
+        let syncDriftLog = [];
+        let syncCheckInterval;
+        let audioContext;
+        let controlsHideTimeout;
+        let isControlsLocked = false;
+        let controlsVisible = true;
+        let isCheckingSync = false;
+        let isInBackgroundTab = false;
+        
+        try {
+            audioContext = new (window.AudioContext || window.webkitAudioContext)();
+        } catch (e) {
+            console.error('Web Audio APIがサポートされていません:', e);
+        }
     
-<script>
-document.addEventListener('DOMContentLoaded', function() {
-    // 同期管理用の変数
-    let lastSyncTime = 0;
-    let isBuffering = false;
-    let syncDriftLog = [];
-    let syncCheckInterval;
-    let audioContext;
-    let controlsHideTimeout;
-    let isControlsLocked = false;
-    let controlsVisible = true;
-    let isCheckingSync = false;
-    let isInBackgroundTab = false;
+        // テクノロジー風背景を生成
+        function createTechBackground() {
+            const bg = document.getElementById('techBg');
+            
+            for (let i = 0; i < 200; i++) {
+                const line = document.createElement('div');
+                line.className = 'circuit-line';
+                
+                const isHorizontal = Math.random() > 0.5;
+                if (isHorizontal) {
+                    line.style.width = `${Math.random() * 300 + 100}px`;
+                    line.style.height = '1px';
+                } else {
+                    line.style.width = '1px';
+                    line.style.height = `${Math.random() * 300 + 100}px`;
+                }
+                
+                line.style.left = `${Math.random() * 100}%`;
+                line.style.top = `${Math.random() * 100}%`;
+                line.style.opacity = Math.random() * 0.5 + 0.1;
+                bg.appendChild(line);
+            }
     
-    try {
-        audioContext = new (window.AudioContext || window.webkitAudioContext)();
-    } catch (e) {
-        console.error('Web Audio APIがサポートされていません:', e);
-    }
-
-    // テクノロジー風背景を生成
-    function createTechBackground() {
-        const bg = document.getElementById('techBg');
+            for (let i = 0; i < 200; i++) {
+                const dot = document.createElement('div');
+                dot.className = 'grid-dot';
+                dot.style.left = `${Math.random() * 100}%`;
+                dot.style.top = `${Math.random() * 100}%`;
+                bg.appendChild(dot);
+            }
+    
+            for (let i = 0; i < 15; i++) {
+                const hex = document.createElement('div');
+                hex.className = 'hexagon';
+                hex.style.left = `${Math.random() * 100}%`;
+                hex.style.top = `${Math.random() * 100}%`;
+                hex.style.transform = `rotate(${Math.random() * 360}deg)`;
+                hex.style.animation = `float ${Math.random() * 10 + 5}s infinite ease-in-out`;
+                bg.appendChild(hex);
+            }
+    
+            for (let i = 0; i < 8; i++) {
+                const pulse = document.createElement('div');
+                pulse.className = 'pulse';
+                pulse.style.left = `${Math.random() * 100}%`;
+                pulse.style.top = `${Math.random() * 100}%`;
+                pulse.style.animationDelay = `${Math.random() * 2}s`;
+                bg.appendChild(pulse);
+            }
+        }
         
-        for (let i = 0; i < 200; i++) {
-            const line = document.createElement('div');
-            line.className = 'circuit-line';
-            
-            const isHorizontal = Math.random() > 0.5;
-            if (isHorizontal) {
-                line.style.width = `${Math.random() * 300 + 100}px`;
-                line.style.height = '1px';
-            } else {
-                line.style.width = '1px';
-                line.style.height = `${Math.random() * 300 + 100}px`;
+        createTechBackground();
+      
+        const urlParams = new URLSearchParams(window.location.search);
+        const isTMode = urlParams.has('mode') && urlParams.get('mode') === 't';
+        const basePath = isTMode ? '/t/' : '/';
+      
+        // ローディング状態を管理
+        let loadingCount = 0;
+        let totalToLoad = 6; // 動画 + 5つの音声ファイル
+        let lastUpdateTime = 0;
+        const updateInterval = 1;
+        
+        function checkLoadingComplete() {
+            loadingCount++;
+            if (loadingCount >= totalToLoad) {
+                setTimeout(function() {
+                    const loadingOverlay = document.getElementById('loadingOverlay');
+                    loadingOverlay.style.opacity = '0';
+                    setTimeout(function() {
+                        loadingOverlay.style.display = 'none';
+                    }, 1000);
+                }, 500);
             }
-            
-            line.style.left = `${Math.random() * 100}%`;
-            line.style.top = `${Math.random() * 100}%`;
-            line.style.opacity = Math.random() * 0.5 + 0.1;
-            bg.appendChild(line);
         }
-
-        for (let i = 0; i < 200; i++) {
-            const dot = document.createElement('div');
-            dot.className = 'grid-dot';
-            dot.style.left = `${Math.random() * 100}%`;
-            dot.style.top = `${Math.random() * 100}%`;
-            bg.appendChild(dot);
+        
+        function handleError(error, message) {
+            console.error(message, error);
+            window.alert(`${message}\n\nエラー詳細: ${error.message}`);
         }
-
-        for (let i = 0; i < 15; i++) {
-            const hex = document.createElement('div');
-            hex.className = 'hexagon';
-            hex.style.left = `${Math.random() * 100}%`;
-            hex.style.top = `${Math.random() * 100}%`;
-            hex.style.transform = `rotate(${Math.random() * 360}deg)`;
-            hex.style.animation = `float ${Math.random() * 10 + 5}s infinite ease-in-out`;
-            bg.appendChild(hex);
+    
+        // 要素を取得
+        const video = document.getElementById('video');
+        video.preservesPitch = true;
+        video.mozPreservesPitch = true; // Firefox用
+        video.webkitPreservesPitch = true; // 古いWebKit用
+        const videoContainer = document.getElementById('video-container');
+        const playPauseBtn = document.getElementById('play-pause-btn');
+        const timeDisplay = document.getElementById('time-display');
+        const progressContainer = document.getElementById('progress-container');
+        const progressBar = document.getElementById('progress-bar');
+        const progressTime = document.getElementById('progress-time');
+        const volumeBtn = document.getElementById('volume-btn');
+        const volumeSlider = document.getElementById('volume-slider');
+        const speedSlider = document.getElementById('speed-slider');
+        const speedValue = document.getElementById('speed-value');
+        const playbackSpeedSlider = document.getElementById('playback-speed');
+        const playbackSpeedValue = document.getElementById('playback-speed-value');
+        const fullscreenBtn = document.getElementById('fullscreen-btn');
+        const startTimeInput = document.getElementById('start-time');
+        const endTimeInput = document.getElementById('end-time');
+        const loopCheckbox = document.getElementById('loop');
+        const globalVolumeSlider = document.getElementById('global-volume');
+        const globalVolumeValue = document.getElementById('global-volume-value');
+        const audioSliders = document.querySelectorAll('.audio-slider');
+        const volumeValues = document.querySelectorAll('.volume-value');
+        const setStartTimeBtn = document.getElementById('set-start-time');
+        const setEndTimeBtn = document.getElementById('set-end-time');
+        const resetEndTimeBtn = document.getElementById('reset-end-time');
+        const disabledOverlay = document.getElementById('disabledOverlay');
+        const combineButton = document.getElementById('combine-button');
+        const combineStatus = document.getElementById('combine-status');
+        const previewSection = document.getElementById('preview-section');
+        const previewButton = document.getElementById('preview-button');
+        const previewTime = document.getElementById('preview-time');
+        const bufferingIndicator = document.getElementById('buffering-indicator');
+        const syncStatus = document.getElementById('sync-status');
+        const syncStatusText = document.getElementById('sync-status-text');
+        const syncStatusClose = document.getElementById('sync-status-close');
+        const lockControlsBtn = document.getElementById('lock-controls-btn');
+        const startMarker = document.getElementById('start-marker');
+        const endMarker = document.getElementById('end-marker');
+        const tempoInput = document.getElementById('tempo');
+        const tempoSpeedValue = document.getElementById('tempo-speed-value');
+        const videoControls = document.querySelector('.video-controls');
+      
+        // 音声オブジェクトを作成
+        const audioElements = {};
+        const audioBuffers = {};
+        const audioFiles = ['p', 'a', 't', 's', 'k'];
+        let combinedAudioElement = null;
+        let isAudioCombined = false;
+        let currentVolumes = { p: 0, a: 1, t: 1, s: 1, k: 0 };
+        
+        // 初期化
+        let videoDuration = 0;
+        let isPlaying = false;
+        let lastVolume = 1;
+        let currentPlaybackRate = 1;
+        let isFullscreen = false;
+    
+        async function enterPiP() {
+        if (!document.pictureInPictureElement && !video.paused) {
+          try {
+            await video.requestPictureInPicture();
+          } catch (err) {
+            console.warn('PiP開始失敗:', err);
+          }
         }
-
-        for (let i = 0; i < 8; i++) {
-            const pulse = document.createElement('div');
-            pulse.className = 'pulse';
-            pulse.style.left = `${Math.random() * 100}%`;
-            pulse.style.top = `${Math.random() * 100}%`;
-            pulse.style.animationDelay = `${Math.random() * 2}s`;
-            bg.appendChild(pulse);
+      }
+    
+      async function exitPiP() {
+        if (document.pictureInPictureElement) {
+          try {
+            await document.exitPictureInPicture();
+          } catch (err) {
+            console.warn('PiP終了失敗:', err);
+          }
         }
-    }
+      }
     
-    createTechBackground();
-  
-    const urlParams = new URLSearchParams(window.location.search);
-    const isTMode = urlParams.has('mode') && urlParams.get('mode') === 't';
-    const basePath = isTMode ? '/t/' : '/';
-  
-    // ローディング状態を管理
-    let loadingCount = 0;
-    let totalToLoad = 6; // 動画 + 5つの音声ファイル
-    let lastUpdateTime = 0;
-    const updateInterval = 1;
+      
+        // 動画のバッファリング状態を監視
+        video.addEventListener('waiting', function() {
+            isBuffering = true;
+            bufferingIndicator.style.display = 'block';
+            if (combinedAudioElement) {
+                combinedAudioElement.pause();
+            }
+        });
+        
+        video.addEventListener('playing', function() {
+            isBuffering = false;
+            bufferingIndicator.style.display = 'none';
+            if (combinedAudioElement && isPlaying) {
+                syncAudioWithVideo();
+            }
+        });
+        
+        video.addEventListener('suspend', function() {
+            console.log('動画の読み込みが一時停止しました');
+        });
+        
+        video.addEventListener('stalled', function() {
+            console.log('動画の読み込みが停滞しました');
+            if (isPlaying) {
+                pauseMedia();
+            }
+        });
     
-    function checkLoadingComplete() {
-        loadingCount++;
-        if (loadingCount >= totalToLoad) {
-            setTimeout(function() {
-                const loadingOverlay = document.getElementById('loadingOverlay');
-                loadingOverlay.style.opacity = '0';
-                setTimeout(function() {
-                    loadingOverlay.style.display = 'none';
-                }, 1000);
-            }, 500);
-        }
+    // startSyncCheck関数を修正
+    function startSyncCheck() {
+      if (isCheckingSync) return;
+      isCheckingSync = true;
+      if (syncCheckInterval) clearInterval(syncCheckInterval);
+      syncCheckInterval = setInterval(checkSync, 1000);
     }
     
-    function handleError(error, message) {
-        console.error(message, error);
-        window.alert(`${message}\n\nエラー詳細: ${error.message}`);
+    // stopSyncCheck関数を修正
+    function stopSyncCheck() {
+      isCheckingSync = false;
+      if (syncCheckInterval) clearInterval(syncCheckInterval);
     }
-
-    // 要素を取得
-    const video = document.getElementById('video');
-    video.preservesPitch = true;
-    video.mozPreservesPitch = true; // Firefox用
-    video.webkitPreservesPitch = true; // 古いWebKit用
-    const videoContainer = document.getElementById('video-container');
-    const playPauseBtn = document.getElementById('play-pause-btn');
-    const timeDisplay = document.getElementById('time-display');
-    const progressContainer = document.getElementById('progress-container');
-    const progressBar = document.getElementById('progress-bar');
-    const progressTime = document.getElementById('progress-time');
-    const volumeBtn = document.getElementById('volume-btn');
-    const volumeSlider = document.getElementById('volume-slider');
-    const speedSlider = document.getElementById('speed-slider');
-    const speedValue = document.getElementById('speed-value');
-    const playbackSpeedSlider = document.getElementById('playback-speed');
-    const playbackSpeedValue = document.getElementById('playback-speed-value');
-    const fullscreenBtn = document.getElementById('fullscreen-btn');
-    const startTimeInput = document.getElementById('start-time');
-    const endTimeInput = document.getElementById('end-time');
-    const loopCheckbox = document.getElementById('loop');
-    const globalVolumeSlider = document.getElementById('global-volume');
-    const globalVolumeValue = document.getElementById('global-volume-value');
-    const audioSliders = document.querySelectorAll('.audio-slider');
-    const volumeValues = document.querySelectorAll('.volume-value');
-    const setStartTimeBtn = document.getElementById('set-start-time');
-    const setEndTimeBtn = document.getElementById('set-end-time');
-    const resetEndTimeBtn = document.getElementById('reset-end-time');
-    const disabledOverlay = document.getElementById('disabledOverlay');
-    const combineButton = document.getElementById('combine-button');
-    const combineStatus = document.getElementById('combine-status');
-    const previewSection = document.getElementById('preview-section');
-    const previewButton = document.getElementById('preview-button');
-    const previewTime = document.getElementById('preview-time');
-    const bufferingIndicator = document.getElementById('buffering-indicator');
-    const syncStatus = document.getElementById('sync-status');
-    const syncStatusText = document.getElementById('sync-status-text');
-    const syncStatusClose = document.getElementById('sync-status-close');
-    const lockControlsBtn = document.getElementById('lock-controls-btn');
-    const startMarker = document.getElementById('start-marker');
-    const endMarker = document.getElementById('end-marker');
-    const tempoInput = document.getElementById('tempo');
-    const tempoSpeedValue = document.getElementById('tempo-speed-value');
-    const videoControls = document.querySelector('.video-controls');
-  
-    // 音声オブジェクトを作成
-    const audioElements = {};
-    const audioBuffers = {};
-    const audioFiles = ['p', 'a', 't', 's', 'k'];
-    let combinedAudioElement = null;
-    let isAudioCombined = false;
-    let currentVolumes = { p: 0, a: 1, t: 1, s: 1, k: 0 };
     
-    // 初期化
-    let videoDuration = 0;
-    let isPlaying = false;
-    let lastVolume = 1;
-    let currentPlaybackRate = 1;
-    let isFullscreen = false;
-
-    async function enterPiP() {
-    if (!document.pictureInPictureElement && !video.paused) {
-      try {
-        await video.requestPictureInPicture();
-      } catch (err) {
-        console.warn('PiP開始失敗:', err);
-      }
-    }
-  }
-
-  async function exitPiP() {
-    if (document.pictureInPictureElement) {
-      try {
-        await document.exitPictureInPicture();
-      } catch (err) {
-        console.warn('PiP終了失敗:', err);
+    // checkSync関数を修正（バックグラウンド時はチェックしない）
+    function checkSync() {
+      if (!isAudioCombined || !isPlaying || isBuffering || isInBackgroundTab) return;
+      
+      const videoTime = video.currentTime;
+      const audioTime = combinedAudioElement.currentTime;
+      const drift = videoTime - audioTime;
+      
+      syncDriftLog.push(drift);
+      if (syncDriftLog.length > 5) syncDriftLog.shift();
+      
+      const avgDrift = syncDriftLog.reduce((a, b) => a + b, 0) / syncDriftLog.length;
+      syncStatusText.textContent = `同期ズレ: ${avgDrift.toFixed(3)}秒`;
+      
+      if (Math.abs(avgDrift) > 0.1) {
+        console.log(`同期ズレを修正: ${avgDrift.toFixed(3)}秒`);
+        syncAudioWithVideo();
       }
     }
-  }
-
-  
-    // 動画のバッファリング状態を監視
-    video.addEventListener('waiting', function() {
-        isBuffering = true;
-        bufferingIndicator.style.display = 'block';
-        if (combinedAudioElement) {
-            combinedAudioElement.pause();
+    
+        // 音声を動画に同期させる関数
+        function syncAudioWithVideo() {
+            if (!isAudioCombined || !isPlaying) return;
+            
+            const currentTime = video.currentTime;
+            
+            if (combinedAudioElement) {
+                combinedAudioElement.currentTime = currentTime;
+                if (isPlaying) {
+                    combinedAudioElement.play().catch(e => console.error('音声再生エラー:', e));
+                }
+            }
+            
+            // ズレ記録をリセット
+            syncDriftLog = [];
+            lastSyncTime = performance.now();
         }
-    });
     
-    video.addEventListener('playing', function() {
-        isBuffering = false;
-        bufferingIndicator.style.display = 'none';
-        if (combinedAudioElement && isPlaying) {
-            syncAudioWithVideo();
+        // 音声ファイルをロード
+        function loadAudioFiles() {
+            audioFiles.forEach(file => {
+                try {
+                    const audio = new Audio(`${basePath}${file}.mp3`);
+                    audio.preload = 'auto';
+                    audio.loop = false;
+                    audioElements[file] = audio;
+                    
+                    audio.addEventListener('loadedmetadata', function() {
+                        console.log(`${basePath}${file}.mp3 loaded`);
+                        checkLoadingComplete();
+                    });
+                    
+                    audio.addEventListener('error', function() {
+                        console.error(`音声ファイル読み込みエラー (${basePath}${file}.mp3):`, audio.error);
+                        checkLoadingComplete();
+                    });
+                } catch (error) {
+                    console.error(`音声ファイル初期化エラー (${basePath}${file}.mp3):`, error);
+                    checkLoadingComplete();
+                }
+            });
         }
-    });
     
-    video.addEventListener('suspend', function() {
-        console.log('動画の読み込みが一時停止しました');
-    });
+        // 音声を結合する関数
+        async function combineAudio() {
+            combineButton.disabled = true;
+            combineStatus.textContent = "音声を合成中...";
     
-    video.addEventListener('stalled', function() {
-        console.log('動画の読み込みが停滞しました');
-        if (isPlaying) {
-            pauseMedia();
-        }
-    });
-
-// startSyncCheck関数を修正
-function startSyncCheck() {
-  if (isCheckingSync) return;
-  isCheckingSync = true;
-  if (syncCheckInterval) clearInterval(syncCheckInterval);
-  syncCheckInterval = setInterval(checkSync, 1000);
-}
-
-// stopSyncCheck関数を修正
-function stopSyncCheck() {
-  isCheckingSync = false;
-  if (syncCheckInterval) clearInterval(syncCheckInterval);
-}
-
-// checkSync関数を修正（バックグラウンド時はチェックしない）
-function checkSync() {
-  if (!isAudioCombined || !isPlaying || isBuffering || isInBackgroundTab) return;
-  
-  const videoTime = video.currentTime;
-  const audioTime = combinedAudioElement.currentTime;
-  const drift = videoTime - audioTime;
-  
-  syncDriftLog.push(drift);
-  if (syncDriftLog.length > 5) syncDriftLog.shift();
-  
-  const avgDrift = syncDriftLog.reduce((a, b) => a + b, 0) / syncDriftLog.length;
-  syncStatusText.textContent = `同期ズレ: ${avgDrift.toFixed(3)}秒`;
-  
-  if (Math.abs(avgDrift) > 0.1) {
-    console.log(`同期ズレを修正: ${avgDrift.toFixed(3)}秒`);
-    syncAudioWithVideo();
-  }
-}
-
-    // 音声を動画に同期させる関数
-    function syncAudioWithVideo() {
-        if (!isAudioCombined || !isPlaying) return;
-        
-        const currentTime = video.currentTime;
-        
-        if (combinedAudioElement) {
-            combinedAudioElement.currentTime = currentTime;
-            if (isPlaying) {
-                combinedAudioElement.play().catch(e => console.error('音声再生エラー:', e));
-            }
-        }
-        
-        // ズレ記録をリセット
-        syncDriftLog = [];
-        lastSyncTime = performance.now();
-    }
-
-    // 音声ファイルをロード
-    function loadAudioFiles() {
-        audioFiles.forEach(file => {
             try {
-                const audio = new Audio(`${basePath}${file}.mp3`);
-                audio.preload = 'auto';
-                audio.loop = false;
-                audioElements[file] = audio;
-                
-                audio.addEventListener('loadedmetadata', function() {
-                    console.log(`${basePath}${file}.mp3 loaded`);
-                    checkLoadingComplete();
+                // 現在の音量設定を保存
+                audioFiles.forEach(file => {
+                    currentVolumes[file] = parseFloat(document.querySelector(`.audio-slider[data-audio="${file}"]`).value);
                 });
-                
-                audio.addEventListener('error', function() {
-                    console.error(`音声ファイル読み込みエラー (${basePath}${file}.mp3):`, audio.error);
-                    checkLoadingComplete();
+    
+                // 各音声ファイルをデコード
+                const audioBufferPromises = audioFiles.map(async file => {
+                    const audio = audioElements[file];
+                    if (!audio) return null;
+    
+                    // 音量が0の場合はスキップ
+                    if (currentVolumes[file] === 0) return null;
+    
+                    const response = await fetch(`${basePath}${file}.mp3`);
+                    const arrayBuffer = await response.arrayBuffer();
+                    return await audioContext.decodeAudioData(arrayBuffer);
                 });
-            } catch (error) {
-                console.error(`音声ファイル初期化エラー (${basePath}${file}.mp3):`, error);
-                checkLoadingComplete();
-            }
-        });
-    }
-
-    // 音声を結合する関数
-    async function combineAudio() {
-        combineButton.disabled = true;
-        combineStatus.textContent = "音声を合成中...";
-
-        try {
-            // 現在の音量設定を保存
-            audioFiles.forEach(file => {
-                currentVolumes[file] = parseFloat(document.querySelector(`.audio-slider[data-audio="${file}"]`).value);
-            });
-
-            // 各音声ファイルをデコード
-            const audioBufferPromises = audioFiles.map(async file => {
-                const audio = audioElements[file];
-                if (!audio) return null;
-
-                // 音量が0の場合はスキップ
-                if (currentVolumes[file] === 0) return null;
-
-                const response = await fetch(`${basePath}${file}.mp3`);
-                const arrayBuffer = await response.arrayBuffer();
-                return await audioContext.decodeAudioData(arrayBuffer);
-            });
-
-            // すべての音声バッファを取得
-            const buffers = await Promise.all(audioBufferPromises);
-            audioFiles.forEach((file, index) => {
-                audioBuffers[file] = buffers[index];
-            });
-
-            // 最長の音声バッファの長さを取得
-            const maxDuration = Math.max(...buffers.filter(b => b).map(b => b.duration));
-
-            // 新しい音声バッファを作成
-            const combinedAudioBuffer = audioContext.createBuffer(
-                2, // ステレオ
-                audioContext.sampleRate * maxDuration,
-                audioContext.sampleRate
-            );
-
-            // 各音声バッファを結合
-            for (let file of audioFiles) {
-                if (!audioBuffers[file] || currentVolumes[file] === 0) continue;
-
-                const buffer = audioBuffers[file];
-                const volume = currentVolumes[file];
-
-                // 各チャンネルに音声を加算
+    
+                // すべての音声バッファを取得
+                const buffers = await Promise.all(audioBufferPromises);
+                audioFiles.forEach((file, index) => {
+                    audioBuffers[file] = buffers[index];
+                });
+    
+                // 最長の音声バッファの長さを取得
+                const maxDuration = Math.max(...buffers.filter(b => b).map(b => b.duration));
+    
+                // 新しい音声バッファを作成
+                const combinedAudioBuffer = audioContext.createBuffer(
+                    2, // ステレオ
+                    audioContext.sampleRate * maxDuration,
+                    audioContext.sampleRate
+                );
+    
+                // 各音声バッファを結合
+                for (let file of audioFiles) {
+                    if (!audioBuffers[file] || currentVolumes[file] === 0) continue;
+    
+                    const buffer = audioBuffers[file];
+                    const volume = currentVolumes[file];
+    
+                    // 各チャンネルに音声を加算
+                    for (let channel = 0; channel < 2; channel++) {
+                        const inputData = buffer.getChannelData(channel % buffer.numberOfChannels);
+                        const outputData = combinedAudioBuffer.getChannelData(channel);
+    
+                        for (let i = 0; i < inputData.length; i++) {
+                            outputData[i] += inputData[i] * volume;
+                        }
+                    }
+                }
+    
+                // 音量を正規化 (クリッピング防止)
                 for (let channel = 0; channel < 2; channel++) {
-                    const inputData = buffer.getChannelData(channel % buffer.numberOfChannels);
                     const outputData = combinedAudioBuffer.getChannelData(channel);
-
-                    for (let i = 0; i < inputData.length; i++) {
-                        outputData[i] += inputData[i] * volume;
+                    let max = 0;
+                    
+                    for (let i = 0; i < outputData.length; i++) {
+                        if (Math.abs(outputData[i]) > max) {
+                            max = Math.abs(outputData[i]);
+                        }
+                    }
+    
+                    if (max > 1) {
+                        for (let i = 0; i < outputData.length; i++) {
+                            outputData[i] /= max;
+                        }
                     }
                 }
-            }
-
-            // 音量を正規化 (クリッピング防止)
-            for (let channel = 0; channel < 2; channel++) {
-                const outputData = combinedAudioBuffer.getChannelData(channel);
-                let max = 0;
+    
+                // AudioBufferをBlobに変換
+                const blob = bufferToWave(combinedAudioBuffer);
+                const url = URL.createObjectURL(blob);
+    
+                // 新しいaudio要素を作成
+                combinedAudioElement = new Audio(url);
+                combinedAudioElement.preservesPitch = true;
+                combinedAudioElement.mozPreservesPitch = true;
+                combinedAudioElement.webkitPreservesPitch = true;
+                combinedAudioElement.playbackRate = currentPlaybackRate;
+    
+                isAudioCombined = true;
+                combineStatus.textContent = "音声の合成が完了しました";
+                enablePlayerControls();
+    
+                previewSection.style.display = 'block';
+    let isCheckingSync = false;
+    let isInBackgroundTab = false;
+    
+    document.addEventListener('visibilitychange', async () => {
+        if (document.hidden) {
+            // タブが非表示になった場合
+            isInBackgroundTab = true;
+            
+            // 動画のみ一時停止（音声は再生を続ける）
+            if (isPlaying) {
+                video.pause();
                 
-                for (let i = 0; i < outputData.length; i++) {
-                    if (Math.abs(outputData[i]) > max) {
-                        max = Math.abs(outputData[i]);
-                    }
+                // 音声は再生を続ける
+                if (combinedAudioElement && !combinedAudioElement.paused) {
+                    // 何もしない（再生を継続）
                 }
-
-                if (max > 1) {
-                    for (let i = 0; i < outputData.length; i++) {
-                        outputData[i] /= max;
+            }
+            
+            try {
+                // PiP表示を試みる
+                if (isPlaying) {
+                    await enterPiP();
+                    if (document.pictureInPictureElement) {
+                        isInBackgroundTab = false;
+                        startSyncCheck();
+                        video.play().catch(e => console.error('PiP再生エラー:', e));
                     }
                 }
+            } catch (e) {
+                console.warn('PiP開始失敗:', e);
+            }
+        } else {
+            // タブが再表示された場合
+            isInBackgroundTab = false;
+            
+            // PiPを終了
+            try {
+                await exitPiP();
+            } catch (e) {
+                console.warn('PiP終了失敗:', e);
             }
-
-            // AudioBufferをBlobに変換
-            const blob = bufferToWave(combinedAudioBuffer);
-            const url = URL.createObjectURL(blob);
-
-            // 新しいaudio要素を作成
-            combinedAudioElement = new Audio(url);
-            combinedAudioElement.preservesPitch = true;
-            combinedAudioElement.mozPreservesPitch = true;
-            combinedAudioElement.webkitPreservesPitch = true;
-            combinedAudioElement.playbackRate = currentPlaybackRate;
-
-            isAudioCombined = true;
-            combineStatus.textContent = "音声の合成が完了しました";
-            enablePlayerControls();
-
-            previewSection.style.display = 'block';
-let isCheckingSync = false;
-let isInBackgroundTab = false;
-
-document.addEventListener('visibilitychange', async () => {
-    if (document.hidden) {
-        // タブが非表示になった場合
-        isInBackgroundTab = true;
-        
-        // 動画のみ一時停止（音声は再生を続ける）
-        if (isPlaying) {
-            video.pause();
             
-            // 音声は再生を続ける
+            // 音声が再生中の場合、動画を音声に同期
             if (combinedAudioElement && !combinedAudioElement.paused) {
-                // 何もしない（再生を継続）
+                video.currentTime = combinedAudioElement.currentTime;
+                video.play().catch(e => console.error('動画再生エラー:', e));
+                isPlaying = true;
+                playPauseBtn.textContent = '⏸';
             }
-        }
-        
-        try {
-            // PiP表示を試みる
+            
+            // 同期チェックを再開
             if (isPlaying) {
-                await enterPiP();
-                if (document.pictureInPictureElement) {
-                    isInBackgroundTab = false;
-                    startSyncCheck();
-                    video.play().catch(e => console.error('PiP再生エラー:', e));
-                }
+                checkSync();
+                startSyncCheck();
             }
-        } catch (e) {
-            console.warn('PiP開始失敗:', e);
-        }
-    } else {
-        // タブが再表示された場合
-        isInBackgroundTab = false;
-        
-        // PiPを終了
-        try {
-            await exitPiP();
-        } catch (e) {
-            console.warn('PiP終了失敗:', e);
-        }
-        
-        // 音声が再生中の場合、動画を音声に同期
-        if (combinedAudioElement && !combinedAudioElement.paused) {
-            video.currentTime = combinedAudioElement.currentTime;
-            video.play().catch(e => console.error('動画再生エラー:', e));
-            isPlaying = true;
-            playPauseBtn.textContent = '⏸';
-        }
-        
-        // 同期チェックを再開
-        if (isPlaying) {
-            checkSync();
-            startSyncCheck();
         }
-    }
-});
-
-
-  // 動画終了時に自動的にPiPを閉じる（次回再開のため）
-  video.addEventListener('ended', exitPiP);
-            // 合成後に音量と再生速度を適用
-            applyVolume();
-            applyPlaybackRate();
-
-        } catch (error) {
-            console.error('音声合成エラー:', error);
-            combineStatus.textContent = "音声の合成に失敗しました";
-            combineButton.disabled = false;
+    });
+    
+    
+      // 動画終了時に自動的にPiPを閉じる（次回再開のため）
+      video.addEventListener('ended', exitPiP);
+                // 合成後に音量と再生速度を適用
+                applyVolume();
+                applyPlaybackRate();
+    
+            } catch (error) {
+                console.error('音声合成エラー:', error);
+                combineStatus.textContent = "音声の合成に失敗しました";
+                combineButton.disabled = false;
+            }
         }
-    }
-
-    function bufferToWave(abuffer) {
-        const numOfChan = abuffer.numberOfChannels,
-            length = abuffer.length * numOfChan * 2 + 44,
-            buffer = new ArrayBuffer(length),
-            view = new DataView(buffer),
-            channels = [],
-            sampleRate = abuffer.sampleRate;
-            
-        // posをletで宣言（constから変更）
-        let pos = 0;
-
-        // write WAV header
-        setUint32(0x46464952); // "RIFF"
-        setUint32(length - 8); // file length - 8
-        setUint32(0x45564157); // "WAVE"
-
-        setUint32(0x20746d66); // "fmt " chunk
-        setUint32(16); // length = 16
-        setUint16(1); // PCM (uncompressed)
-        setUint16(numOfChan);
-        setUint32(sampleRate);
-        setUint32(sampleRate * 2 * numOfChan);
-        setUint16(numOfChan * 2);
-        setUint16(16);
-
-        setUint32(0x61746164); // "data" - chunk
-        setUint32(length - pos - 4);
-
-        // write interleaved data
-        for (let i = 0; i < abuffer.length; i++) {
-            for (let channel = 0; channel < numOfChan; channel++) {
-                let sample = abuffer.getChannelData(channel)[i] * 0x7fff;
-                if (sample < -32768) sample = -32768;
-                if (sample > 32767) sample = 32767;
-                view.setInt16(pos, sample, true);
+    
+        function bufferToWave(abuffer) {
+            const numOfChan = abuffer.numberOfChannels,
+                length = abuffer.length * numOfChan * 2 + 44,
+                buffer = new ArrayBuffer(length),
+                view = new DataView(buffer),
+                channels = [],
+                sampleRate = abuffer.sampleRate;
+                
+            // posをletで宣言（constから変更）
+            let pos = 0;
+    
+            // write WAV header
+            setUint32(0x46464952); // "RIFF"
+            setUint32(length - 8); // file length - 8
+            setUint32(0x45564157); // "WAVE"
+    
+            setUint32(0x20746d66); // "fmt " chunk
+            setUint32(16); // length = 16
+            setUint16(1); // PCM (uncompressed)
+            setUint16(numOfChan);
+            setUint32(sampleRate);
+            setUint32(sampleRate * 2 * numOfChan);
+            setUint16(numOfChan * 2);
+            setUint16(16);
+    
+            setUint32(0x61746164); // "data" - chunk
+            setUint32(length - pos - 4);
+    
+            // write interleaved data
+            for (let i = 0; i < abuffer.length; i++) {
+                for (let channel = 0; channel < numOfChan; channel++) {
+                    let sample = abuffer.getChannelData(channel)[i] * 0x7fff;
+                    if (sample < -32768) sample = -32768;
+                    if (sample > 32767) sample = 32767;
+                    view.setInt16(pos, sample, true);
+                    pos += 2;
+                }
+            }
+    
+            function setUint16(data) {
+                view.setUint16(pos, data, true);
                 pos += 2;
             }
-        }
-
-        function setUint16(data) {
-            view.setUint16(pos, data, true);
-            pos += 2;
-        }
-
-        function setUint32(data) {
-            view.setUint32(pos, data, true);
-            pos += 4;
-        }
-
-        return new Blob([buffer], { type: 'audio/wav' });
-    }
-
-    function applyVolume() {
-        if (!isAudioCombined) return;
-        
-        // ベース音量 (0-1)
-        const baseVolume = parseFloat(volumeSlider.value);
-        // グローバル音量係数 (0-10)
-        const globalVolume = parseFloat(globalVolumeSlider.value) / 10; // 0-1に変換
-        
-        // 最終音量 (0-1)
-        const finalVolume = Math.max(0, Math.min(1, baseVolume * globalVolume));
-        
-        // 動画と音声の音量を設定
-        video.volume = finalVolume;
-        if (combinedAudioElement) {
-            combinedAudioElement.volume = finalVolume;
-        }
-        
-        // 音量アイコンを更新
-        updateVolumeIcon();
-    }
-
-    function applyPlaybackRate() {
-        if (!isAudioCombined) return;
-        
-        const speed = parseFloat(playbackSpeedSlider.value);
-        currentPlaybackRate = speed;
-        video.playbackRate = speed;
-        
-        if (combinedAudioElement) {
-            combinedAudioElement.playbackRate = speed;
-        }
-        
-        speedValue.textContent = speed.toFixed(2) + 'x';
-        playbackSpeedValue.textContent = speed.toFixed(2) + 'x';
-        speedSlider.value = speed;
-    }
-
-    // プレイヤーコントロールを有効化
-    function enablePlayerControls() {
-        disabledOverlay.style.display = 'none';
-        playPauseBtn.disabled = false;
-        volumeBtn.disabled = false;
-        volumeSlider.disabled = false;
-        speedSlider.disabled = false;
-        fullscreenBtn.disabled = false;
-        startTimeInput.disabled = false;
-        endTimeInput.disabled = false;
-        resetEndTimeBtn.disabled = false;
-        loopCheckbox.disabled = false;
-        globalVolumeSlider.disabled = false;
-        setStartTimeBtn.disabled = false;
-        setEndTimeBtn.disabled = false;
-        playbackSpeedSlider.disabled = false;
-    }
-
-    // プレビュー再生
-    function togglePreview() {
-        if (!isAudioCombined || !combinedAudioElement) return;
-
-        if (previewButton.textContent === '▶') {
-            // 再生
-            combinedAudioElement.currentTime = 0;
-            combinedAudioElement.play()
-                .then(() => {
-                    previewButton.textContent = '⏸';
-                    
-                    // プレビューの時間表示を更新
-                    const updatePreviewTime = () => {
-                        if (!combinedAudioElement || !isAudioCombined) return;
-                        
-                        const currentTime = combinedAudioElement.currentTime;
-                        const duration = combinedAudioElement.duration;
-                        
-                        if (currentTime >= duration) {
-                            previewButton.textContent = '▶';
-                            previewTime.textContent = `00:00 / ${formatTime(duration)}`;
-                            return;
-                        }
-                        
-                        previewTime.textContent = `${formatTime(currentTime)} / ${formatTime(duration)}`;
-                        requestAnimationFrame(updatePreviewTime);
-                    };
-                    
-                    updatePreviewTime();
-                })
-                .catch(e => console.error('プレビュー再生エラー:', e));
-        } else {
-            // 一時停止
-            combinedAudioElement.pause();
-            previewButton.textContent = '▶';
-        }
-    }
-
-    // 時間をフォーマットするヘルパー関数
-    function formatTime(seconds) {
-        const mins = Math.floor(seconds / 60);
-        const secs = Math.floor(seconds % 60);
-        return `${String(mins).padStart(2, '0')}:${String(secs).padStart(2, '0')}`;
-    }
-
-    // 動画のメタデータが読み込まれたら
-    video.addEventListener('loadedmetadata', function() {
-        try {
-            videoDuration = video.duration;
-            endTimeInput.value = videoDuration.toFixed(2);
-            endTimeInput.max = videoDuration;
-            startTimeInput.max = videoDuration - 0.1;
-            updateTimeDisplay();
-            checkLoadingComplete();
-        } catch (error) {
-            handleError(error, '動画メタデータ読み込み中にエラーが発生しました');
-        }
-    });
     
-    // 動画エラー処理
-    video.addEventListener('error', function() {
-        handleError(video.error, '動画読み込み中にエラーが発生しました');
-    });
+            function setUint32(data) {
+                view.setUint32(pos, data, true);
+                pos += 4;
+            }
     
-    // 再生ボタンクリック
-    playPauseBtn.addEventListener('click', function() {
-        const endTime = parseFloat(endTimeInput.value) || videoDuration;
-        if (video.currentTime >= endTime) {
-            const startTime = parseFloat(startTimeInput.value) || 0;
-            seekMedia(startTime);
+            return new Blob([buffer], { type: 'audio/wav' });
         }
-        togglePlayPause();
-    });
     
-    // 時間表示を更新
-    function updateTimeDisplay() {
-        const now = performance.now();
-        if (now - lastUpdateTime < updateInterval && !isFullscreen) return;
-        lastUpdateTime = now;
-        
-        try {
-            const currentTime = video.currentTime;
-            const duration = video.duration || videoDuration;
+        function applyVolume() {
+            if (!isAudioCombined) return;
             
-            const currentMinutes = Math.floor(currentTime / 60);
-            const currentSeconds = Math.floor(currentTime % 60);
-            const currentMilliseconds = Math.floor((currentTime % 1) * 100);
-            const durationMinutes = Math.floor(duration / 60);
-            const durationSeconds = Math.floor(duration % 60);
-            const durationMilliseconds = Math.floor((duration % 1) * 100);
+            // ベース音量 (0-1)
+            const baseVolume = parseFloat(volumeSlider.value);
+            // グローバル音量係数 (0-10)
+            const globalVolume = parseFloat(globalVolumeSlider.value) / 10; // 0-1に変換
             
-            timeDisplay.textContent = 
-                `${String(currentMinutes).padStart(2, '0')}:${String(currentSeconds).padStart(2, '0')}.${String(currentMilliseconds).padStart(2, '0')} / ` +
-                `${String(durationMinutes).padStart(2, '0')}:${String(durationSeconds).padStart(2, '0')}.${String(durationMilliseconds).padStart(2, '0')}`;
+            // 最終音量 (0-1)
+            const finalVolume = Math.max(0, Math.min(1, baseVolume * globalVolume));
             
-            const progressPercent = (currentTime / duration) * 100;
-            progressBar.style.width = `${progressPercent}%`;
-        } catch (error) {
-            console.error('時間表示更新エラー:', error);
+            // 動画と音声の音量を設定
+            video.volume = finalVolume;
+            if (combinedAudioElement) {
+                combinedAudioElement.volume = finalVolume;
+            }
+            
+            // 音量アイコンを更新
+            updateVolumeIcon();
         }
-    }
     
-    // 再生/一時停止をトグル
-    function togglePlayPause() {
-        if (isPlaying) {
-            pauseMedia();
-        } else {
-            playMedia();
+        function applyPlaybackRate() {
+            if (!isAudioCombined) return;
+            
+            const speed = parseFloat(playbackSpeedSlider.value);
+            currentPlaybackRate = speed;
+            video.playbackRate = speed;
+            
+            if (combinedAudioElement) {
+                combinedAudioElement.playbackRate = speed;
+            }
+            
+            speedValue.textContent = speed.toFixed(2) + 'x';
+            playbackSpeedValue.textContent = speed.toFixed(2) + 'x';
+            speedSlider.value = speed;
         }
-    }
     
-function playMedia() {
-    try {
-        const duration = video.duration || videoDuration;
-        const startTime = parseFloat(startTimeInput.value) || 0;
-        const endTime = parseFloat(endTimeInput.value) || duration;
-        
-        if (video.currentTime >= endTime) {
-            video.currentTime = startTime;
+        // プレイヤーコントロールを有効化
+        function enablePlayerControls() {
+            disabledOverlay.style.display = 'none';
+            playPauseBtn.disabled = false;
+            volumeBtn.disabled = false;
+            volumeSlider.disabled = false;
+            speedSlider.disabled = false;
+            fullscreenBtn.disabled = false;
+            startTimeInput.disabled = false;
+            endTimeInput.disabled = false;
+            resetEndTimeBtn.disabled = false;
+            loopCheckbox.disabled = false;
+            globalVolumeSlider.disabled = false;
+            setStartTimeBtn.disabled = false;
+            setEndTimeBtn.disabled = false;
+            playbackSpeedSlider.disabled = false;
+        }
+    
+        // プレビュー再生
+        function togglePreview() {
+            if (!isAudioCombined || !combinedAudioElement) return;
+    
+            if (previewButton.textContent === '▶') {
+                // 再生
+                combinedAudioElement.currentTime = 0;
+                combinedAudioElement.play()
+                    .then(() => {
+                        previewButton.textContent = '⏸';
+                        
+                        // プレビューの時間表示を更新
+                        const updatePreviewTime = () => {
+                            if (!combinedAudioElement || !isAudioCombined) return;
+                            
+                            const currentTime = combinedAudioElement.currentTime;
+                            const duration = combinedAudioElement.duration;
+                            
+                            if (currentTime >= duration) {
+                                previewButton.textContent = '▶';
+                                previewTime.textContent = `00:00 / ${formatTime(duration)}`;
+                                return;
+                            }
+                            
+                            previewTime.textContent = `${formatTime(currentTime)} / ${formatTime(duration)}`;
+                            requestAnimationFrame(updatePreviewTime);
+                        };
+                        
+                        updatePreviewTime();
+                    })
+                    .catch(e => console.error('プレビュー再生エラー:', e));
+            } else {
+                // 一時停止
+                combinedAudioElement.pause();
+                previewButton.textContent = '▶';
+            }
         }
+    
+        // 時間をフォーマットするヘルパー関数
+        function formatTime(seconds) {
+            const mins = Math.floor(seconds / 60);
+            const secs = Math.floor(seconds % 60);
+            return `${String(mins).padStart(2, '0')}:${String(secs).padStart(2, '0')}`;
+        }
+    
+        // 動画のメタデータが読み込まれたら
+        video.addEventListener('loadedmetadata', function() {
+            try {
+                videoDuration = video.duration;
+                endTimeInput.value = videoDuration.toFixed(2);
+                endTimeInput.max = videoDuration;
+                startTimeInput.max = videoDuration - 0.1;
+                updateTimeDisplay();
+                checkLoadingComplete();
+            } catch (error) {
+                handleError(error, '動画メタデータ読み込み中にエラーが発生しました');
+            }
+        });
         
-        const playPromise = video.play();
+        // 動画エラー処理
+        video.addEventListener('error', function() {
+            handleError(video.error, '動画読み込み中にエラーが発生しました');
+        });
         
-        if (playPromise !== undefined) {
-            playPromise.then(() => {
-                isPlaying = true;
-                playPauseBtn.textContent = '⏸';
+        // 再生ボタンクリック
+        playPauseBtn.addEventListener('click', function() {
+            const endTime = parseFloat(endTimeInput.value) || videoDuration;
+            if (video.currentTime >= endTime) {
+                const startTime = parseFloat(startTimeInput.value) || 0;
+                seekMedia(startTime);
+            }
+            togglePlayPause();
+        });
+        
+        // 時間表示を更新
+        function updateTimeDisplay() {
+            const now = performance.now();
+            if (now - lastUpdateTime < updateInterval && !isFullscreen) return;
+            lastUpdateTime = now;
+            
+            try {
+                const currentTime = video.currentTime;
+                const duration = video.duration || videoDuration;
                 
-                // 音声を同期して再生
-                if (isAudioCombined) {
-                    combinedAudioElement.currentTime = video.currentTime;
-                    combinedAudioElement.play().catch(e => console.error('音声再生エラー:', e));
-                }
+                const currentMinutes = Math.floor(currentTime / 60);
+                const currentSeconds = Math.floor(currentTime % 60);
+                const currentMilliseconds = Math.floor((currentTime % 1) * 100);
+                const durationMinutes = Math.floor(duration / 60);
+                const durationSeconds = Math.floor(duration % 60);
+                const durationMilliseconds = Math.floor((duration % 1) * 100);
                 
-                startSyncCheck();
+                timeDisplay.textContent = 
+                    `${String(currentMinutes).padStart(2, '0')}:${String(currentSeconds).padStart(2, '0')}.${String(currentMilliseconds).padStart(2, '0')} / ` +
+                    `${String(durationMinutes).padStart(2, '0')}:${String(durationSeconds).padStart(2, '0')}.${String(durationMilliseconds).padStart(2, '0')}`;
                 
-                video.playbackRate = currentPlaybackRate;
-            }).catch(error => {
-                console.error('動画再生エラー:', error);
-                isPlaying = false;
-                playPauseBtn.textContent = '▶';
-            });
+                const progressPercent = (currentTime / duration) * 100;
+                progressBar.style.width = `${progressPercent}%`;
+            } catch (error) {
+                console.error('時間表示更新エラー:', error);
+            }
         }
-    } catch (error) {
-        console.error('メディア再生エラー:', error);
-        isPlaying = false;
-        playPauseBtn.textContent = '▶';
-    }
-}
-
-function pauseMedia() {
-    try {
-        video.pause();
-        isPlaying = false;
-        playPauseBtn.textContent = '▶';
-        stopSyncCheck();
-        
-        if (combinedAudioElement) {
-            combinedAudioElement.pause();
-        }
-    } catch (error) {
-        console.error('メディア一時停止エラー:', error);
-    }
-}
-    
-    // 時間更新時の処理
-    video.addEventListener('timeupdate', function() {
-        const duration = video.duration || videoDuration;
-        const endTime = parseFloat(endTimeInput.value) || duration;
         
-        if (video.currentTime >= endTime && endTime > 0) {
-            if (loopCheckbox.checked) {
-                const startTime = parseFloat(startTimeInput.value) || 0;
-                video.currentTime = startTime;
-                syncAudioWithVideo();
-            } else {
+        // 再生/一時停止をトグル
+        function togglePlayPause() {
+            if (isPlaying) {
                 pauseMedia();
-                video.currentTime = endTime;
+            } else {
+                playMedia();
             }
         }
         
-        updateTimeDisplay();
-    });
-    
-    // プログレスバークリックでシーク
-    progressContainer.addEventListener('click', function(e) {
-        if (!video.duration) return;
-        
-        const rect = this.getBoundingClientRect();
-        const pos = (e.clientX - rect.left) / rect.width;
-        const seekTime = pos * video.duration;
-        
-        seekMedia(seekTime);
-    });
-    
-    // 指定した時間にシーク (改良版)
-    function seekMedia(time) {
+    function playMedia() {
         try {
             const duration = video.duration || videoDuration;
             const startTime = parseFloat(startTimeInput.value) || 0;
             const endTime = parseFloat(endTimeInput.value) || duration;
             
-            const seekTime = Math.max(startTime, Math.min(time, endTime));
-            video.currentTime = seekTime;
+            if (video.currentTime >= endTime) {
+                video.currentTime = startTime;
+            }
+            
+            const playPromise = video.play();
             
-            if (combinedAudioElement) {
-                combinedAudioElement.currentTime = seekTime;
-                if (isPlaying) {
-                    combinedAudioElement.play().catch(e => console.error('音声再生エラー:', e));
-                }
+            if (playPromise !== undefined) {
+                playPromise.then(() => {
+                    isPlaying = true;
+                    playPauseBtn.textContent = '⏸';
+                    
+                    // 音声を同期して再生
+                    if (isAudioCombined) {
+                        combinedAudioElement.currentTime = video.currentTime;
+                        combinedAudioElement.play().catch(e => console.error('音声再生エラー:', e));
+                    }
+                    
+                    startSyncCheck();
+                    
+                    video.playbackRate = currentPlaybackRate;
+                }).catch(error => {
+                    console.error('動画再生エラー:', error);
+                    isPlaying = false;
+                    playPauseBtn.textContent = '▶';
+                });
             }
         } catch (error) {
-            console.error('メディアシークエラー:', error);
+            console.error('メディア再生エラー:', error);
+            isPlaying = false;
+            playPauseBtn.textContent = '▶';
         }
     }
     
-    // プログレスバー上でマウス移動時に時間を表示
-    progressContainer.addEventListener('mousemove', function(e) {
-        if (!video.duration) return;
+    function pauseMedia() {
+        try {
+            video.pause();
+            isPlaying = false;
+            playPauseBtn.textContent = '▶';
+            stopSyncCheck();
+            
+            if (combinedAudioElement) {
+                combinedAudioElement.pause();
+            }
+        } catch (error) {
+            console.error('メディア一時停止エラー:', error);
+        }
+    }
         
-        const rect = this.getBoundingClientRect();
-        const pos = (e.clientX - rect.left) / rect.width;
-        const hoverTime = pos * video.duration;
+        // 時間更新時の処理
+        video.addEventListener('timeupdate', function() {
+            const duration = video.duration || videoDuration;
+            const endTime = parseFloat(endTimeInput.value) || duration;
+            
+            if (video.currentTime >= endTime && endTime > 0) {
+                if (loopCheckbox.checked) {
+                    const startTime = parseFloat(startTimeInput.value) || 0;
+                    video.currentTime = startTime;
+                    syncAudioWithVideo();
+                } else {
+                    pauseMedia();
+                    video.currentTime = endTime;
+                }
+            }
+            
+            updateTimeDisplay();
+        });
         
-        const minutes = Math.floor(hoverTime / 60);
-        const seconds = Math.floor(hoverTime % 60);
-        const milliseconds = Math.floor((hoverTime % 1) * 100);
+        // プログレスバークリックでシーク
+        progressContainer.addEventListener('click', function(e) {
+            if (!video.duration) return;
+            
+            const rect = this.getBoundingClientRect();
+            const pos = (e.clientX - rect.left) / rect.width;
+            const seekTime = pos * video.duration;
+            
+            seekMedia(seekTime);
+        });
         
-        progressTime.textContent = `${String(minutes).padStart(2, '0')}:${String(seconds).padStart(2, '0')}.${String(milliseconds).padStart(2, '0')}`;
-        progressTime.style.display = 'block';
-        progressTime.style.left = `${pos * 100}%`;
-    });
-    
-    progressContainer.addEventListener('mouseleave', function() {
-        progressTime.style.display = 'none';
-    });
-    
-    // 動画クリックで再生/一時停止
-    video.addEventListener('click', function() {
-        togglePlayPause();
-    });
-
-    volumeSlider.addEventListener('input', function() {
-        if (!isAudioCombined) return;
+        // 指定した時間にシーク (改良版)
+        function seekMedia(time) {
+            try {
+                const duration = video.duration || videoDuration;
+                const startTime = parseFloat(startTimeInput.value) || 0;
+                const endTime = parseFloat(endTimeInput.value) || duration;
+                
+                const seekTime = Math.max(startTime, Math.min(time, endTime));
+                video.currentTime = seekTime;
+                
+                if (combinedAudioElement) {
+                    combinedAudioElement.currentTime = seekTime;
+                    if (isPlaying) {
+                        combinedAudioElement.play().catch(e => console.error('音声再生エラー:', e));
+                    }
+                }
+            } catch (error) {
+                console.error('メディアシークエラー:', error);
+            }
+        }
         
-        lastVolume = parseFloat(this.value);
-        applyVolume();
-    });
-    
-    volumeBtn.addEventListener('click', function() {
-        if (!isAudioCombined) return;
+        // プログレスバー上でマウス移動時に時間を表示
+        progressContainer.addEventListener('mousemove', function(e) {
+            if (!video.duration) return;
+            
+            const rect = this.getBoundingClientRect();
+            const pos = (e.clientX - rect.left) / rect.width;
+            const hoverTime = pos * video.duration;
+            
+            const minutes = Math.floor(hoverTime / 60);
+            const seconds = Math.floor(hoverTime % 60);
+            const milliseconds = Math.floor((hoverTime % 1) * 100);
+            
+            progressTime.textContent = `${String(minutes).padStart(2, '0')}:${String(seconds).padStart(2, '0')}.${String(milliseconds).padStart(2, '0')}`;
+            progressTime.style.display = 'block';
+            progressTime.style.left = `${pos * 100}%`;
+        });
         
-        if (video.volume > 0) {
-            lastVolume = parseFloat(volumeSlider.value);
-            volumeSlider.value = 0;
-        } else {
-            volumeSlider.value = lastVolume;
-        }
+        progressContainer.addEventListener('mouseleave', function() {
+            progressTime.style.display = 'none';
+        });
         
-        applyVolume();
-    });
-    
-    // 音量アイコンを更新
-    function updateVolumeIcon() {
-        if (video.volume === 0) {
-            volumeBtn.textContent = '🔇';
-        } else if (video.volume < 3) {
-            volumeBtn.textContent = '🔈';
-        } else {
-            volumeBtn.textContent = '🔊';
-        }
-    }
-    
-    // 再生速度スライダー (動画プレイヤー)
-    speedSlider.addEventListener('input', function() {
-        if (!isAudioCombined) return;
-        
-        const speed = parseFloat(this.value);
-        speedValue.textContent = speed.toFixed(2) + 'x';
-        playbackSpeedSlider.value = speed;
-        playbackSpeedValue.textContent = speed.toFixed(2) + 'x';
-        updatePlaybackRate(speed);
-    });
-    
-    // 再生速度スライダー (設定メニュー)
-    playbackSpeedSlider.addEventListener('input', function() {
-        if (!isAudioCombined) return;
-        
-        const speed = parseFloat(this.value);
-        playbackSpeedValue.textContent = speed.toFixed(2) + 'x';
-        speedSlider.value = speed;
-        speedValue.textContent = speed.toFixed(2) + 'x';
-        updatePlaybackRate(speed);
-    });
+        // 動画クリックで再生/一時停止
+        video.addEventListener('click', function() {
+            togglePlayPause();
+        });
     
-    // テンポ入力による再生速度更新
-    tempoInput.addEventListener('input', function() {
-        const tempo = parseFloat(this.value);
-        const baseTempo = isTMode ? 66 : 92;
-        const speed = tempo / baseTempo;
+        volumeSlider.addEventListener('input', function() {
+            if (!isAudioCombined) return;
+            
+            lastVolume = parseFloat(this.value);
+            applyVolume();
+        });
         
-        const clampedSpeed = Math.max(0.001, Math.min(5.0, speed));
+        volumeBtn.addEventListener('click', function() {
+            if (!isAudioCombined) return;
+            
+            if (video.volume > 0) {
+                lastVolume = parseFloat(volumeSlider.value);
+                volumeSlider.value = 0;
+            } else {
+                volumeSlider.value = lastVolume;
+            }
+            
+            applyVolume();
+        });
         
-        playbackSpeedSlider.value = clampedSpeed;
-        playbackSpeedValue.textContent = clampedSpeed.toFixed(2) + 'x';
-        speedSlider.value = clampedSpeed;
-        speedValue.textContent = clampedSpeed.toFixed(2) + 'x';
-        tempoSpeedValue.textContent = clampedSpeed.toFixed(2) + 'x';
+        // 音量アイコンを更新
+        function updateVolumeIcon() {
+            if (video.volume === 0) {
+                volumeBtn.textContent = '🔇';
+            } else if (video.volume < 3) {
+                volumeBtn.textContent = '🔈';
+            } else {
+                volumeBtn.textContent = '🔊';
+            }
+        }
         
-        updatePlaybackRate(clampedSpeed);
-    });
-    
-    function updatePlaybackRate(speed) {
-        if (!isAudioCombined) return;
+        // 再生速度スライダー (動画プレイヤー)
+        speedSlider.addEventListener('input', function() {
+            if (!isAudioCombined) return;
+            
+            const speed = parseFloat(this.value);
+            speedValue.textContent = speed.toFixed(2) + 'x';
+            playbackSpeedSlider.value = speed;
+            playbackSpeedValue.textContent = speed.toFixed(2) + 'x';
+            updatePlaybackRate(speed);
+        });
         
-        currentPlaybackRate = speed;
-        video.playbackRate = speed;
+        // 再生速度スライダー (設定メニュー)
+        playbackSpeedSlider.addEventListener('input', function() {
+            if (!isAudioCombined) return;
+            
+            const speed = parseFloat(this.value);
+            playbackSpeedValue.textContent = speed.toFixed(2) + 'x';
+            speedSlider.value = speed;
+            speedValue.textContent = speed.toFixed(2) + 'x';
+            updatePlaybackRate(speed);
+        });
         
-        // ピッチ保持を再設定
-        video.preservesPitch = true;
-        video.mozPreservesPitch = true;
-        video.webkitPreservesPitch = true;
+        // テンポ入力による再生速度更新
+        tempoInput.addEventListener('input', function() {
+            const tempo = parseFloat(this.value);
+            const baseTempo = isTMode ? 66 : 92;
+            const speed = tempo / baseTempo;
+            
+            const clampedSpeed = Math.max(0.001, Math.min(5.0, speed));
+            
+            playbackSpeedSlider.value = clampedSpeed;
+            playbackSpeedValue.textContent = clampedSpeed.toFixed(2) + 'x';
+            speedSlider.value = clampedSpeed;
+            speedValue.textContent = clampedSpeed.toFixed(2) + 'x';
+            tempoSpeedValue.textContent = clampedSpeed.toFixed(2) + 'x';
+            
+            updatePlaybackRate(clampedSpeed);
+        });
         
-        if (combinedAudioElement) {
-            combinedAudioElement.playbackRate = speed;
+        function updatePlaybackRate(speed) {
+            if (!isAudioCombined) return;
             
-            // 合成音声のピッチ保持を設定
-            combinedAudioElement.preservesPitch = true;
-            combinedAudioElement.mozPreservesPitch = true;
-            combinedAudioElement.webkitPreservesPitch = true;
-        }
-    }
-    
-    // 全画面ボタン
-    fullscreenBtn.addEventListener('click', function() {
-        if (!isFullscreen) {
-            if (videoContainer.requestFullscreen) {
-                videoContainer.requestFullscreen();
-            } else if (videoContainer.webkitRequestFullscreen) {
-                videoContainer.webkitRequestFullscreen();
-            } else if (videoContainer.msRequestFullscreen) {
-                videoContainer.msRequestFullscreen();
-            }
-        } else {
-            if (document.exitFullscreen) {
-                document.exitFullscreen();
-            } else if (document.webkitExitFullscreen) {
-                document.webkitExitFullscreen();
-            } else if (document.msExitFullscreen) {
-                document.msExitFullscreen();
+            currentPlaybackRate = speed;
+            video.playbackRate = speed;
+            
+            // ピッチ保持を再設定
+            video.preservesPitch = true;
+            video.mozPreservesPitch = true;
+            video.webkitPreservesPitch = true;
+            
+            if (combinedAudioElement) {
+                combinedAudioElement.playbackRate = speed;
+                
+                // 合成音声のピッチ保持を設定
+                combinedAudioElement.preservesPitch = true;
+                combinedAudioElement.mozPreservesPitch = true;
+                combinedAudioElement.webkitPreservesPitch = true;
             }
         }
-    });
-    
-    // 全画面変更イベント
-    document.addEventListener('fullscreenchange', handleFullscreenChange);
-    document.addEventListener('webkitfullscreenchange', handleFullscreenChange);
-    document.addEventListener('msfullscreenchange', handleFullscreenChange);
-    
-    function handleFullscreenChange() {
-        isFullscreen = !!(document.fullscreenElement || document.webkitFullscreenElement || document.msFullscreenElement);
-        fullscreenBtn.textContent = isFullscreen ? '⛶' : '⛶';
-        video.controls = false;
         
-        // 全画面時にロックボタンを表示
-        lockControlsBtn.style.display = isFullscreen ? 'flex' : 'none';
+        // 全画面ボタン
+        fullscreenBtn.addEventListener('click', function() {
+            if (!isFullscreen) {
+                if (videoContainer.requestFullscreen) {
+                    videoContainer.requestFullscreen();
+                } else if (videoContainer.webkitRequestFullscreen) {
+                    videoContainer.webkitRequestFullscreen();
+                } else if (videoContainer.msRequestFullscreen) {
+                    videoContainer.msRequestFullscreen();
+                }
+            } else {
+                if (document.exitFullscreen) {
+                    document.exitFullscreen();
+                } else if (document.webkitExitFullscreen) {
+                    document.webkitExitFullscreen();
+                } else if (document.msExitFullscreen) {
+                    document.msExitFullscreen();
+                }
+            }
+        });
+        
+        // 全画面変更イベント
+        document.addEventListener('fullscreenchange', handleFullscreenChange);
+        document.addEventListener('webkitfullscreenchange', handleFullscreenChange);
+        document.addEventListener('msfullscreenchange', handleFullscreenChange);
         
-        // 全画面時にコントロールバー自動非表示機能を有効化
-        if (isFullscreen) {
-            resetControlsHideTimer();
-            document.addEventListener('mousemove', handleFullscreenMouseMove);
-        } else {
-            document.removeEventListener('mousemove', handleFullscreenMouseMove);
-            clearTimeout(controlsHideTimeout);
-            showControls();
-        }
-    }
-    
-    // 全画面時のマウス移動処理
-    function handleFullscreenMouseMove() {
-        if (!isControlsLocked) {
-            showControls();
-            resetControlsHideTimer();
+        function handleFullscreenChange() {
+            isFullscreen = !!(document.fullscreenElement || document.webkitFullscreenElement || document.msFullscreenElement);
+            fullscreenBtn.textContent = isFullscreen ? '⛶' : '⛶';
+            video.controls = false;
+            
+            // 全画面時にロックボタンを表示
+            lockControlsBtn.style.display = isFullscreen ? 'flex' : 'none';
+            
+            // 全画面時にコントロールバー自動非表示機能を有効化
+            if (isFullscreen) {
+                resetControlsHideTimer();
+                document.addEventListener('mousemove', handleFullscreenMouseMove);
+            } else {
+                document.removeEventListener('mousemove', handleFullscreenMouseMove);
+                clearTimeout(controlsHideTimeout);
+                showControls();
+            }
         }
-    }
-    
-    // コントロールバーを表示
-    function showControls() {
-        if (!controlsVisible) {
-            videoControls.style.opacity = '1';
-            controlsVisible = true;
+        
+        // 全画面時のマウス移動処理
+        function handleFullscreenMouseMove() {
+            if (!isControlsLocked) {
+                showControls();
+                resetControlsHideTimer();
+            }
         }
-    }
-    
-    // コントロールバーを非表示
-    function hideControls() {
-        if (!isControlsLocked && controlsVisible) {
-            videoControls.style.opacity = '0';
-            controlsVisible = false;
+        
+        // コントロールバーを表示
+        function showControls() {
+            if (!controlsVisible) {
+                videoControls.style.opacity = '1';
+                controlsVisible = true;
+            }
         }
-    }
-    
-    // コントロールバー非表示タイマーをリセット
-    function resetControlsHideTimer() {
-        clearTimeout(controlsHideTimeout);
-        if (!isControlsLocked) {
-            controlsHideTimeout = setTimeout(hideControls, 1500); // 1.5秒後に非表示
+        
+        // コントロールバーを非表示
+        function hideControls() {
+            if (!isControlsLocked && controlsVisible) {
+                videoControls.style.opacity = '0';
+                controlsVisible = false;
+            }
         }
-    }
-    
-    // ロックボタンのクリック処理
-    lockControlsBtn.addEventListener('click', function() {
-        isControlsLocked = !isControlsLocked;
-        this.classList.toggle('locked', isControlsLocked);
         
-        if (isControlsLocked) {
-            showControls();
+        // コントロールバー非表示タイマーをリセット
+        function resetControlsHideTimer() {
             clearTimeout(controlsHideTimeout);
-        } else {
-            resetControlsHideTimer();
-        }
-    });
-    
-    // キーボードイベント (ESCで全画面終了)
-    document.addEventListener('keydown', function(e) {
-        if (e.key === 'Escape' && isFullscreen) {
-            if (document.exitFullscreen) {
-                document.exitFullscreen();
-            } else if (document.webkitExitFullscreen) {
-                document.webkitExitFullscreen();
-            } else if (document.msExitFullscreen) {
-                document.msExitFullscreen();
+            if (!isControlsLocked) {
+                controlsHideTimeout = setTimeout(hideControls, 1500); // 1.5秒後に非表示
             }
         }
-    });
-    
-    // ボリュームスライダーのイベント
-    audioSliders.forEach((slider, index) => {
-        slider.addEventListener('input', function() {
+        
+        // ロックボタンのクリック処理
+        lockControlsBtn.addEventListener('click', function() {
+            isControlsLocked = !isControlsLocked;
+            this.classList.toggle('locked', isControlsLocked);
+            
+            if (isControlsLocked) {
+                showControls();
+                clearTimeout(controlsHideTimeout);
+            } else {
+                resetControlsHideTimer();
+            }
+        });
+        
+        // キーボードイベント (ESCで全画面終了)
+        document.addEventListener('keydown', function(e) {
+            if (e.key === 'Escape' && isFullscreen) {
+                if (document.exitFullscreen) {
+                    document.exitFullscreen();
+                } else if (document.webkitExitFullscreen) {
+                    document.webkitExitFullscreen();
+                } else if (document.msExitFullscreen) {
+                    document.msExitFullscreen();
+                }
+            }
+        });
+        
+        // ボリュームスライダーのイベント
+        audioSliders.forEach((slider, index) => {
+            slider.addEventListener('input', function() {
+                const value = parseFloat(this.value);
+                volumeValues[index].textContent = value.toFixed(2);
+                
+                const percent = value * 100;
+                this.style.backgroundSize = `${percent}% 100%`;
+            });
+        });
+        
+        globalVolumeSlider.addEventListener('input', function() {
             const value = parseFloat(this.value);
-            volumeValues[index].textContent = value.toFixed(2);
+            globalVolumeValue.textContent = value.toFixed(1);
             
-            const percent = value * 100;
+            const percent = (value - this.min) / (this.max - this.min) * 100;
             this.style.backgroundSize = `${percent}% 100%`;
+            
+            applyVolume();
         });
-    });
-    
-    globalVolumeSlider.addEventListener('input', function() {
-        const value = parseFloat(this.value);
-        globalVolumeValue.textContent = value.toFixed(1);
         
-        const percent = (value - this.min) / (this.max - this.min) * 100;
-        this.style.backgroundSize = `${percent}% 100%`;
+        // ループ設定変更時
+        loopCheckbox.addEventListener('change', function() {
+            // 合成音声ではループは動画に依存する
+        });
         
-        applyVolume();
-    });
-    
-    // ルー���設定変更時
-    loopCheckbox.addEventListener('change', function() {
-        // 合成音声ではループは動画に依存する
-    });
-    
-    // 現在の秒数を開始時間に設定
-    setStartTimeBtn.addEventListener('click', function() {
-        startTimeInput.value = video.currentTime.toFixed(2);
-        updateProgressMarkers();
-    });
-    
-    // 現在の秒数を終了時間に設定
-    setEndTimeBtn.addEventListener('click', function() {
-        endTimeInput.value = video.currentTime.toFixed(2);
-        updateProgressMarkers();
-    });
-    
-    // 終了時間を動画の長さにリセット
-    resetEndTimeBtn.addEventListener('click', function() {
-        endTimeInput.value = video.duration.toFixed(2);
-        updateProgressMarkers();
-    });
-    
-    // プログレスバーのマーカーを更新
-    function updateProgressMarkers() {
-        const duration = video.duration || videoDuration;
-        const startTime = parseFloat(startTimeInput.value) || 0;
-        const endTime = parseFloat(endTimeInput.value) || duration;
-        
-        if (duration > 0) {
-            startMarker.style.left = `${(startTime / duration) * 100}%`;
-            endMarker.style.left = `${(endTime / duration) * 100}%`;
+        // 現在の秒数を開始時間に設定
+        setStartTimeBtn.addEventListener('click', function() {
+            startTimeInput.value = video.currentTime.toFixed(2);
+            updateProgressMarkers();
+        });
+        
+        // 現在の秒数を終了時間に設定
+        setEndTimeBtn.addEventListener('click', function() {
+            endTimeInput.value = video.currentTime.toFixed(2);
+            updateProgressMarkers();
+        });
+        
+        // 終了時間を動画の長さにリセット
+        resetEndTimeBtn.addEventListener('click', function() {
+            endTimeInput.value = video.duration.toFixed(2);
+            updateProgressMarkers();
+        });
+        
+        // プログレスバーのマーカーを更新
+        function updateProgressMarkers() {
+            const duration = video.duration || videoDuration;
+            const startTime = parseFloat(startTimeInput.value) || 0;
+            const endTime = parseFloat(endTimeInput.value) || duration;
             
-            startMarker.style.display = 'block';
-            endMarker.style.display = 'block';
-        }
-    }
-    
-    // 開始/終了時間変更時にマーカーを更新
-    startTimeInput.addEventListener('input', updateProgressMarkers);
-    endTimeInput.addEventListener('input', updateProgressMarkers);
-    
-    // 合成ボタンクリック
-    combineButton.addEventListener('click', combineAudio);
-    
-    // プレビューボタンクリック
-    previewButton.addEventListener('click', togglePreview);
-    
-    // 同期ステータスを閉じる
-    syncStatusClose.addEventListener('click', function() {
-        syncStatus.style.display = 'none';
-    });
-    
-    // 初期化
-    loadAudioFiles();
-    updateVolumeIcon();
-    volumeSlider.value = video.volume;
-    video.controls = false;
-    
-    // スライダーの背景を初期化
-    function initSliderBackgrounds() {
-        const sliders = [
-            volumeSlider, 
-            speedSlider, 
-            globalVolumeSlider, 
-            playbackSpeedSlider, 
-            ...audioSliders
-        ];
-        
-        sliders.forEach(slider => {
-            if (slider) {
-                slider.style.backgroundImage = 'linear-gradient(#64ffda, #64ffda)';
-                slider.style.backgroundRepeat = 'no-repeat';
+            if (duration > 0) {
+                startMarker.style.left = `${(startTime / duration) * 100}%`;
+                endMarker.style.left = `${(endTime / duration) * 100}%`;
                 
-                if (slider === globalVolumeSlider) {
-                    const percent = (slider.value - slider.min) / (slider.max - slider.min) * 100;
-                    slider.style.backgroundSize = `${percent}% 100%`;
-                    globalVolumeValue.textContent = slider.value;
-                } else {
-                    slider.style.backgroundSize = `${slider.value * 100}% 100%`;
-                }
+                startMarker.style.display = 'block';
+                endMarker.style.display = 'block';
             }
+        }
+        
+        // 開始/終了時間変更時にマーカーを更新
+        startTimeInput.addEventListener('input', updateProgressMarkers);
+        endTimeInput.addEventListener('input', updateProgressMarkers);
+        
+        // 合成ボタンクリック
+        combineButton.addEventListener('click', combineAudio);
+        
+        // プレビューボタンクリック
+        previewButton.addEventListener('click', togglePreview);
+        
+        // 同期ステータスを閉じる
+        syncStatusClose.addEventListener('click', function() {
+            syncStatus.style.display = 'none';
         });
-    }
-    
-    initSliderBackgrounds();
-    startSyncCheck(); // 同期チェックを開始
-    
-    // 初期テンポ設定
-    tempoInput.value = isTMode ? 66 : 92;
-    tempoInput.dispatchEvent(new Event('input'));
-});
-          document.addEventListener('DOMContentLoaded', function() {
-            // URLパラメータをチェック
-            const urlParams = new URLSearchParams(window.location.search);
-            const isTMode = urlParams.has('mode') && urlParams.get('mode') === 't';
-            
-            // タイムマーカーデータ
-            const timeMarkers = isTMode ? [
-                { label: '①', time: 15.2 },
-                { label: '②', time: 43.8 },
-                { label: '①[2番]', time: 79.0 },
-                { label: '②[2番]', time: 108.0 },
-                { label: '③', time: 137.25 },
-                { label: '④', time: 162.55 },
-                { label: '⑤', time: 191.65 }
-            ] : [
-                { label: 'A', time: 8.35 },
-                { label: 'B', time: 72.1 },
-                { label: 'C', time: 98.67 },
-                { label: 'D', time: 155.83 },
-                { label: 'E', time: 192.55 }
+        
+        // 初期化
+        loadAudioFiles();
+        updateVolumeIcon();
+        volumeSlider.value = video.volume;
+        video.controls = false;
+        
+        // スライダーの背景を初期化
+        function initSliderBackgrounds() {
+            const sliders = [
+                volumeSlider, 
+                speedSlider, 
+                globalVolumeSlider, 
+                playbackSpeedSlider, 
+                ...audioSliders
             ];
             
-            // タイムマーカーを表示
-            const timeMarkersContainer = document.getElementById('time-markers-container');
-            
-            timeMarkers.forEach(marker => {
-                const markerElement = document.createElement('div');
-                markerElement.className = 'time-marker';
-                markerElement.textContent = `${marker.label}(${marker.time}秒)`;
-                markerElement.dataset.time = marker.time;
-                
-                // ドラッグ開始
-                markerElement.addEventListener('dragstart', function(e) {
-                    e.dataTransfer.setData('text/plain', marker.time);
-                    this.classList.add('dragging');
-                });
-                
-                // ドラッグ終了
-                markerElement.addEventListener('dragend', function() {
-                    this.classList.remove('dragging');
-                });
+            sliders.forEach(slider => {
+                if (slider) {
+                    slider.style.backgroundImage = 'linear-gradient(#64ffda, #64ffda)';
+                    slider.style.backgroundRepeat = 'no-repeat';
+                    
+                    if (slider === globalVolumeSlider) {
+                        const percent = (slider.value - slider.min) / (slider.max - slider.min) * 100;
+                        slider.style.backgroundSize = `${percent}% 100%`;
+                        globalVolumeValue.textContent = slider.value;
+                    } else {
+                        slider.style.backgroundSize = `${slider.value * 100}% 100%`;
+                    }
+                }
+            });
+        }
+        
+        initSliderBackgrounds();
+        startSyncCheck(); // 同期チェックを開始
+        
+        // 初期テンポ設定
+        tempoInput.value = isTMode ? 66 : 92;
+        tempoInput.dispatchEvent(new Event('input'));
+    });
+              document.addEventListener('DOMContentLoaded', function() {
+                // URLパラメータをチェック
+                const urlParams = new URLSearchParams(window.location.search);
+                const isTMode = urlParams.has('mode') && urlParams.get('mode') === 't';
                 
-                // ドラッグ可能に設定
-                markerElement.draggable = true;
+                // タイムマーカーデータ
+                const timeMarkers = isTMode ? [
+                    { label: '①', time: 15.2 },
+                    { label: '②', time: 43.8 },
+                    { label: '①[2番]', time: 79.0 },
+                    { label: '②[2番]', time: 108.0 },
+                    { label: '③', time: 137.25 },
+                    { label: '④', time: 162.55 },
+                    { label: '⑤', time: 191.65 }
+                ] : [
+                    { label: 'A', time: 8.35 },
+                    { label: 'B', time: 72.1 },
+                    { label: 'C', time: 98.67 },
+                    { label: 'D', time: 155.83 },
+                    { label: 'E', time: 192.55 }
+                ];
                 
-                // クリックで開始時間に設定
-                markerElement.addEventListener('click', function() {
-                    document.getElementById('start-time').value = marker.time;
-                    updateProgressMarkers();
-                });
+                // タイムマー��ーを表示
+                const timeMarkersContainer = document.getElementById('time-markers-container');
                 
-                timeMarkersContainer.appendChild(markerElement);
-            });
-            
-            // ドロップターゲットの設定
-            const startTimeInput = document.getElementById('start-time');
-            const endTimeInput = document.getElementById('end-time');
-            
-            [startTimeInput, endTimeInput].forEach(input => {
-                // ドラッグオーバー
-                input.addEventListener('dragover', function(e) {
-                    e.preventDefault();
-                    this.style.backgroundColor = 'rgba(100, 255, 218, 0.2)';
+                timeMarkers.forEach(marker => {
+                    const markerElement = document.createElement('div');
+                    markerElement.className = 'time-marker';
+                    markerElement.textContent = `${marker.label}(${marker.time}秒)`;
+                    markerElement.dataset.time = marker.time;
+                    
+                    // ドラッグ開始
+                    markerElement.addEventListener('dragstart', function(e) {
+                        e.dataTransfer.setData('text/plain', marker.time);
+                        this.classList.add('dragging');
+                    });
+                    
+                    // ドラッグ終了
+                    markerElement.addEventListener('dragend', function() {
+                        this.classList.remove('dragging');
+                    });
+                    
+                    // ドラッグ可能に設定
+                    markerElement.draggable = true;
+                    
+                    // クリックで開始時間に設定
+                    markerElement.addEventListener('click', function() {
+                        document.getElementById('start-time').value = marker.time;
+                        updateProgressMarkers();
+                    });
+                    
+                    timeMarkersContainer.appendChild(markerElement);
                 });
                 
-                // ドラッグリーブ
-                input.addEventListener('dragleave', function() {
-                    this.style.backgroundColor = '';
-                });
+                // ドロップターゲットの設定
+                const startTimeInput = document.getElementById('start-time');
+                const endTimeInput = document.getElementById('end-time');
                 
-                // ドロップ
-                input.addEventListener('drop', function(e) {
-                    e.preventDefault();
-                    this.style.backgroundColor = '';
+                [startTimeInput, endTimeInput].forEach(input => {
+                    // ドラッグオーバー
+                    input.addEventListener('dragover', function(e) {
+                        e.preventDefault();
+                        this.style.backgroundColor = 'rgba(100, 255, 218, 0.2)';
+                    });
                     
-                    const time = parseFloat(e.dataTransfer.getData('text/plain'));
-                    if (!isNaN(time)) {
-                        this.value = time;
-                        updateProgressMarkers();
-                    }
+                    // ドラッグリーブ
+                    input.addEventListener('dragleave', function() {
+                        this.style.backgroundColor = '';
+                    });
+                    
+                    // ドロップ
+                    input.addEventListener('drop', function(e) {
+                        e.preventDefault();
+                        this.style.backgroundColor = '';
+                        
+                        const time = parseFloat(e.dataTransfer.getData('text/plain'));
+                        if (!isNaN(time)) {
+                            this.value = time;
+                            updateProgressMarkers();
+                        }
+                    });
                 });
-            });
-            
-            // 入力ボックスの変更時にマーカーを更新
-            startTimeInput.addEventListener('input', updateProgressMarkers);
-            endTimeInput.addEventListener('input', updateProgressMarkers);
-            
-            // 既存のupdateProgressMarkers関数を再利用
-            function updateProgressMarkers() {
-                const duration = video.duration || videoDuration;
-                const startTime = parseFloat(startTimeInput.value) || 0;
-                const endTime = parseFloat(endTimeInput.value) || duration;
                 
-                if (duration > 0) {
-                    startMarker.style.left = `${(startTime / duration) * 100}%`;
-                    endMarker.style.left = `${(endTime / duration) * 100}%`;
+                // 入力ボックスの変更時にマーカーを更新
+                startTimeInput.addEventListener('input', updateProgressMarkers);
+                endTimeInput.addEventListener('input', updateProgressMarkers);
+                
+                // 既存のupdateProgressMarkers関数を再利用
+                function updateProgressMarkers() {
+                    const duration = video.duration || videoDuration;
+                    const startTime = parseFloat(startTimeInput.value) || 0;
+                    const endTime = parseFloat(endTimeInput.value) || duration;
                     
-                    startMarker.style.display = 'block';
-                    endMarker.style.display = 'block';
+                    if (duration > 0) {
+                        startMarker.style.left = `${(startTime / duration) * 100}%`;
+                        endMarker.style.left = `${(endTime / duration) * 100}%`;
+                        
+                        startMarker.style.display = 'block';
+                        endMarker.style.display = 'block';
+                    }
                 }
-            }
-        });
-</script>
+            });
+    </script>
 </body>
+
 </html>
\ No newline at end of file
