(function() {
  // グローバル変数宣言
  let dtContextMenu = null;
  let dtSelectedElement = null;
  let dtSelectedDOMNode = null;
  let dtActiveEditElement = null;
  let dtNetworkRequests = [];
  let dtSelectedRequest = null;
  let dtObserver = null;
  let dtRefreshElementsPanel = null;

  // DOM変更を監視するMutationObserver (最適化版)
  const setupMutationObserver = () => {
    if (dtObserver) dtObserver.disconnect();
    
    dtObserver = new MutationObserver(() => {
      if (dtRefreshElementsPanel) {
        dtRefreshElementsPanel();
      }
    });

    dtObserver.observe(document.documentElement, {
      childList: true,
      subtree: true,
      attributes: false,
      characterData: false
    });
  };

  // スタイルの追加 (すべてのクラスにdt-プレフィックス)
  const style = document.createElement('style');
  style.textContent = `
.dt-devtools-container {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 300px;
  background-color: var(--dt-bg-color);
  border-top: 1px solid var(--dt-border-color);
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.3);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--dt-text-color);
}

.dt-devtools-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 5px 10px;
  background-color: var(--dt-tab-bg);
  border-bottom: 1px solid var(--dt-border-color);
}

.dt-devtools-tabs {
  display: flex;
  gap: 5px;
}

.dt-devtools-tab {
  padding: 5px 10px;
  cursor: pointer;
  border-radius: 3px 3px 0 0;
  background-color: var(--dt-tab-bg);
  border: 1px solid var(--dt-border-color);
  border-bottom: none;
  font-size: 12px;
  color: var(--dt-text-muted);
}

.dt-devtools-tab.active {
  background-color: var(--dt-tab-active-bg);
  color: var(--dt-text-color);
  border-bottom: 1px solid var(--dt-tab-active-bg);
  margin-bottom: -1px;
  font-weight: bold;
}

.dt-devtools-close {
  background: none;
  border: none;
  font-size: 16px;
  cursor: pointer;
  padding: 0 5px;
  color: var(--dt-text-color);
}

.dt-devtools-content {
  flex: 1;
  overflow: auto;
  position: relative;
  background-color: var(--dt-panel-bg);
}

.dt-devtools-panel {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  padding: 10px;
  overflow: auto;
  display: none;
  background-color: var(--dt-panel-bg);
}

.dt-devtools-panel.active {
  display: block;
}

/* Console スタイル */
#dt-console-log {
  white-space: pre-wrap;
  margin: 0;
  line-height: 1.4;
  flex: 1;
  color: var(--dt-console-log-color);
  font-family: 'Consolas', 'Monaco', monospace;
  font-size: 13px;
}

.dt-console-log {
  color: var(--dt-console-log-color);
}

.dt-console-error {
  color: var(--dt-console-error-color);
}

.dt-console-warn {
  color: var(--dt-console-warn-color);
}

.dt-console-info {
  color: var(--dt-console-info-color);
}

.dt-console-input {
  width: calc(100% - 16px);
  background: var(--dt-tab-bg);
  border: 1px solid var(--dt-border-color);
  color: var(--dt-text-color);
  padding: 8px;
  margin-top: 10px;
  font-family: monospace;
  border-radius: 3px;
}

/* Elements スタイル */
.dt-elements-container {
  display: flex;
  flex: 1;
  overflow: hidden;
}

.dt-dom-tree {
  font-family: 'Consolas', 'Monaco', monospace;
  flex: 1;
  overflow: auto;
  border-right: 1px solid var(--dt-border-color);
  padding-right: 10px;
  color: var(--dt-dom-text);
  font-size: 13px;
}

.dt-dom-node {
  margin-left: 15px;
  position: relative;
  line-height: 1.4;
  transition: background-color 0.3s;
}

.dt-dom-node.selected {
  background: var(--dt-highlight-bg);
}

.dt-dom-node.highlight {
  animation: dt-highlight-fade 1.5s;
}

@keyframes dt-highlight-fade {
  0% { background-color: rgba(79, 195, 247, 0.5); }
  100% { background-color: transparent; }
}

.dt-dom-tag {
  color: var(--dt-dom-tag);
  font-weight: bold;
}

.dt-dom-attr {
  color: var(--dt-dom-attr);
}

.dt-dom-attr.editable:hover {
  text-decoration: underline;
  cursor: pointer;
}

.dt-dom-text {
  color: var(--dt-dom-text);
}

.dt-dom-edit-input {
  background: var(--dt-panel-bg);
  border: 1px solid var(--dt-primary-color);
  padding: 0 2px;
  margin: -1px 0;
  font-family: monospace;
  min-width: 50px;
  color: var(--dt-text-color);
}

.dt-css-panel {
  flex: 1;
  overflow: auto;
  padding-left: 10px;
  font-size: 13px;
}

.dt-css-rule {
  margin-bottom: 15px;
  border: 1px solid var(--dt-border-color);
  padding: 8px;
  background-color: var(--dt-tab-bg);
  border-radius: 3px;
}

.dt-css-selector {
  color: var(--dt-primary-color);
  margin-bottom: 5px;
  font-weight: bold;
}

.dt-css-property {
  display: flex;
  margin-bottom: 3px;
}

.dt-css-property-name {
  color: var(--dt-dom-attr);
  min-width: 120px;
}

.dt-css-property-value {
  color: var(--dt-dom-text);
  flex: 1;
}

.dt-css-toggle {
  margin-left: 10px;
  color: var(--dt-error-color);
  cursor: pointer;
}

/* Context Menu */
.dt-context-menu {
  position: absolute;
  background: var(--dt-panel-bg);
  border: 1px solid var(--dt-border-color);
  z-index: 10000;
  min-width: 200px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  display: none;
  border-radius: 3px;
  overflow: hidden;
}

.dt-context-menu-item {
  padding: 8px 15px;
  cursor: pointer;
  color: var(--dt-text-color);
  font-size: 13px;
}

.dt-context-menu-item:hover {
  background: var(--dt-primary-color);
  color: #000;
}

/* Storage スタイル */
.dt-storage-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 10px;
  font-size: 13px;
}

.dt-storage-table th, .dt-storage-table td {
  border: 1px solid var(--dt-border-color);
  padding: 5px;
  text-align: left;
}

.dt-storage-table th {
  background: var(--dt-tab-bg);
}

.dt-storage-actions {
  display: flex;
  gap: 5px;
}

.dt-storage-btn {
  background: var(--dt-primary-color);
  border: none;
  padding: 2px 5px;
  cursor: pointer;
  border-radius: 3px;
  color: #000;
  font-size: 12px;
}

.dt-editable {
  cursor: pointer;
  padding: 2px 5px;
  border: 1px dashed transparent;
}

.dt-editable:hover {
  border-color: var(--dt-primary-color);
}

.dt-add-btn {
  background: var(--dt-primary-color);
  color: #000;
  border: none;
  padding: 5px 10px;
  margin-top: 10px;
  cursor: pointer;
  border-radius: 3px;
  font-size: 13px;
}

.dt-add-btn:hover {
  background: var(--dt-primary-hover);
}

/* Network スタイル */
.dt-network-container {
  display: flex;
  height: 100%;
  overflow: hidden;
}

.dt-network-requests {
  width: 40%;
  overflow-y: auto;
  border-right: 1px solid var(--dt-border-color);
  font-size: 13px;
}

.dt-network-details {
  width: 60%;
  overflow-y: auto;
  padding-left: 10px;
}

.dt-network-request {
  padding: 8px;
  border-bottom: 1px solid var(--dt-border-color);
  cursor: pointer;
  display: flex;
  align-items: center;
}

.dt-network-request:hover {
  background-color: rgba(0, 122, 204, 0.1);
}

.dt-network-request.selected {
  background-color: var(--dt-highlight-bg);
}

.dt-network-status {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: 8px;
  flex-shrink: 0;
}

.dt-network-status.success {
  background-color: var(--dt-success-color);
  color: white;
}

.dt-network-status.error {
  background-color: var(--dt-error-color);
  color: white;
}

.dt-network-method {
  font-weight: bold;
  margin-right: 8px;
  color: var(--dt-primary-color);
  min-width: 40px;
}

.dt-network-url {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.dt-network-time {
  color: var(--dt-text-muted);
  font-size: 11px;
  margin-left: 8px;
}

.dt-network-detail-section {
  margin-bottom: 15px;
}

.dt-network-detail-title {
  font-weight: bold;
  margin-bottom: 5px;
  color: var(--dt-primary-color);
}

.dt-network-detail-content {
  background: var(--dt-tab-bg);
  padding: 8px;
  border-radius: 3px;
  border: 1px solid var(--dt-border-color);
  font-family: monospace;
  white-space: pre-wrap;
  font-size: 12px;
  max-height: 200px;
  overflow-y: auto;
}

/* DOM Tree Toggle */
.dt-dom-toggle {
  position: absolute;
  left: -12px;
  top: 2px;
  width: 10px;
  height: 10px;
  cursor: pointer;
  background-color: var(--dt-text-muted);
  clip-path: polygon(0 0, 100% 50%, 0 100%);
  transition: transform 0.2s;
}

.dt-dom-toggle.collapsed {
  transform: rotate(-90deg);
}

.dt-dom-children {
  overflow: hidden;
  transition: max-height 0.3s ease-out;
}

/* JSON スタイル */
.dt-json-key {
  color: var(--dt-json-key);
}

.dt-json-string {
  color: var(--dt-json-string);
}

.dt-json-number {
  color: var(--dt-json-number);
}

.dt-json-boolean {
  color: var(--dt-json-boolean);
}

.dt-json-null {
  color: var(--dt-json-null);
}

/* CSS変数定義 */
:root {
  --dt-bg-color: #1e1e1e;
  --dt-panel-bg: #252526;
  --dt-border-color: #3c3c3c;
  --dt-text-color: #e0e0e0;
  --dt-text-muted: #a0a0a0;
  --dt-primary-color: #007acc;
  --dt-primary-hover: #3e9fda;
  --dt-success-color: #4caf50;
  --dt-error-color: #f44336;
  --dt-warning-color: #ff9800;
  --dt-info-color: #2196f3;
  --dt-highlight-bg: rgba(0, 122, 204, 0.2);
  --dt-tab-bg: #2d2d2d;
  --dt-tab-active-bg: #1e1e1e;
  --dt-console-log-color: #e0e0e0;
  --dt-console-error-color: #f44336;
  --dt-console-warn-color: #ff9800;
  --dt-console-info-color: #4fc3f7;
  --dt-json-key: #9cdcfe;
  --dt-json-string: #ce9178;
  --dt-json-number: #b5cea8;
  --dt-json-boolean: #569cd6;
  --dt-json-null: #569cd6;
  --dt-dom-tag: #569cd6;
  --dt-dom-attr: #9cdcfe;
  --dt-dom-text: #d4d4d4;
}
  `;
  document.head.appendChild(style);

  // 開発者ツールのメイン関数
  const createDevTools = () => {
    const container = document.createElement('div');
    container.className = 'dt-devtools-container';
    container.id = 'dt-devtools-container';
    container.style.display = 'none';

    // ヘッダー部分
    const header = document.createElement('div');
    header.className = 'dt-devtools-header';

    const tabs = document.createElement('div');
    tabs.className = 'dt-devtools-tabs';

    const consoleTab = createTab('Console', 'console');
    const elementsTab = createTab('Elements', 'elements');
    const networkTab = createTab('Network', 'network');
    const storageTab = createTab('Storage', 'storage');

    tabs.appendChild(consoleTab);
    tabs.appendChild(elementsTab);
    tabs.appendChild(networkTab);
    tabs.appendChild(storageTab);

    const closeBtn = document.createElement('button');
    closeBtn.className = 'dt-devtools-close';
    closeBtn.textContent = '×';
    closeBtn.onclick = toggleDevTools;

    header.appendChild(tabs);
    header.appendChild(closeBtn);

    // コンテンツ部分
    const content = document.createElement('div');
    content.className = 'dt-devtools-content';

    const consolePanel = createConsolePanel();
    const elementsPanel = createElementsPanel();
    const networkPanel = createNetworkPanel();
    const storagePanel = createStoragePanel();

    content.appendChild(consolePanel);
    content.appendChild(elementsPanel);
    content.appendChild(networkPanel);
    content.appendChild(storagePanel);

    container.appendChild(header);
    container.appendChild(content);

    document.body.appendChild(container);

    // コンテキストメニュー作成
    createContextMenu();

    // タブ切り替え機能
    function createTab(name, panelId) {
      const tab = document.createElement('div');
      tab.className = 'dt-devtools-tab';
      tab.textContent = name;
      tab.onclick = () => {
        document.querySelectorAll('.dt-devtools-tab').forEach(t => t.classList.remove('active'));
        document.querySelectorAll('.dt-devtools-panel').forEach(p => p.classList.remove('active'));
        tab.classList.add('active');
        document.getElementById(panelId + '-panel').classList.add('active');
        
        if (panelId === 'network') {
          renderNetworkRequests();
        }
      };
      return tab;
    }

    elementsTab.click();
  };

  // ネットワークパネル作成
  function createNetworkPanel() {
    const panel = document.createElement('div');
    panel.className = 'dt-devtools-panel';
    panel.id = 'network-panel';

    const container = document.createElement('div');
    container.className = 'dt-network-container';
    panel.appendChild(container);

    // リクエストリスト
    const requestsList = document.createElement('div');
    requestsList.className = 'dt-network-requests';
    container.appendChild(requestsList);

    // 詳細パネル
    const detailsPanel = document.createElement('div');
    detailsPanel.className = 'dt-network-details';
    container.appendChild(detailsPanel);

    // ネットワークリクエストを監視
    setupNetworkMonitoring();

    return panel;
  }

  // ネットワーク監視を設定
  function setupNetworkMonitoring() {
    const originalFetch = window.fetch;
    window.fetch = async function(...args) {
      const [input, init] = args;
      const url = typeof input === 'string' ? input : input.url;
      const method = (init && init.method) || 'GET';
      const startTime = performance.now();

      const requestData = {
        id: Math.random().toString(36).substr(2, 9),
        url,
        method,
        status: 'pending',
        startTime,
        endTime: null,
        duration: null,
        requestHeaders: init ? init.headers : null,
        requestBody: init ? init.body : null,
        response: null,
        error: null
      };

      dtNetworkRequests.push(requestData);
      renderNetworkRequests();

      try {
        const response = await originalFetch.apply(this, args);
        const endTime = performance.now();

        requestData.status = response.ok ? 'success' : 'error';
        requestData.endTime = endTime;
        requestData.duration = endTime - startTime;
        requestData.response = {
          status: response.status,
          statusText: response.statusText,
          headers: Object.fromEntries(response.headers.entries()),
          body: null
        };

        const clonedResponse = response.clone();
        const contentType = clonedResponse.headers.get('content-type') || '';

        if (contentType.includes('application/json')) {
          requestData.response.body = await clonedResponse.json();
        } else {
          requestData.response.body = await clonedResponse.text();
        }

        renderNetworkRequests();
        return response;
      } catch (error) {
        const endTime = performance.now();
        requestData.status = 'error';
        requestData.endTime = endTime;
        requestData.duration = endTime - startTime;
        requestData.error = {
          name: error.name,
          message: error.message,
          stack: error.stack
        };

        renderNetworkRequests();
        throw error;
      }
    };

    const originalOpen = XMLHttpRequest.prototype.open;
    const originalSend = XMLHttpRequest.prototype.send;

    XMLHttpRequest.prototype.open = function(method, url) {
      this._method = method;
      this._url = url;
      this._startTime = performance.now();
      this._requestHeaders = {};
      
      const originalSetRequestHeader = this.setRequestHeader;
      this.setRequestHeader = function(header, value) {
        this._requestHeaders[header] = value;
        originalSetRequestHeader.call(this, header, value);
      };
      
      return originalOpen.apply(this, arguments);
    };

    XMLHttpRequest.prototype.send = function(body) {
      const requestData = {
        id: Math.random().toString(36).substr(2, 9),
        url: this._url,
        method: this._method,
        status: 'pending',
        startTime: this._startTime,
        endTime: null,
        duration: null,
        requestHeaders: this._requestHeaders,
        requestBody: body,
        response: null,
        error: null
      };

      dtNetworkRequests.push(requestData);
      renderNetworkRequests();

      this.addEventListener('load', function() {
        const endTime = performance.now();
        requestData.status = this.status >= 200 && this.status < 300 ? 'success' : 'error';
        requestData.endTime = endTime;
        requestData.duration = endTime - requestData.startTime;
        
        try {
          const contentType = this.getResponseHeader('content-type') || '';
          requestData.response = {
            status: this.status,
            statusText: this.statusText,
            headers: { 'content-type': contentType },
            body: contentType.includes('application/json') ? 
              JSON.parse(this.responseText) : this.responseText
          };
        } catch (e) {
          requestData.response = {
            status: this.status,
            statusText: this.statusText,
            headers: {},
            body: this.responseText
          };
        }

        renderNetworkRequests();
      });

      this.addEventListener('error', function() {
        const endTime = performance.now();
        requestData.status = 'error';
        requestData.endTime = endTime;
        requestData.duration = endTime - requestData.startTime;
        requestData.error = {
          name: 'NetworkError',
          message: 'Network request failed'
        };

        renderNetworkRequests();
      });

      return originalSend.call(this, body);
    };
  }

  // ネットワークリクエストを表示
  function renderNetworkRequests() {
    const panel = document.getElementById('network-panel');
    if (!panel || !panel.classList.contains('active')) return;

    const requestsList = panel.querySelector('.dt-network-requests');
    const detailsPanel = panel.querySelector('.dt-network-details');

    requestsList.innerHTML = '';
    
    dtNetworkRequests.forEach(request => {
      const requestElement = document.createElement('div');
      requestElement.className = 'dt-network-request';
      if (dtSelectedRequest && dtSelectedRequest.id === request.id) {
        requestElement.classList.add('selected');
      }
      
      requestElement.onclick = () => {
        dtSelectedRequest = request;
        renderNetworkRequests();
        renderNetworkDetails();
      };
      
      const statusElement = document.createElement('div');
      statusElement.className = `dt-network-status ${request.status}`;
      statusElement.textContent = request.status === 'success' ? '✓' : '✕';
      
      const methodElement = document.createElement('div');
      methodElement.className = 'dt-network-method';
      methodElement.textContent = request.method;
      
      const urlElement = document.createElement('div');
      urlElement.className = 'dt-network-url';
      urlElement.textContent = request.url;
      
      const timeElement = document.createElement('div');
      timeElement.className = 'dt-network-time';
      timeElement.textContent = request.duration ? `${Math.round(request.duration)}ms` : '';
      
      requestElement.appendChild(statusElement);
      requestElement.appendChild(methodElement);
      requestElement.appendChild(urlElement);
      requestElement.appendChild(timeElement);
      
      requestsList.appendChild(requestElement);
    });
  }

  // ネットワークリクエストの詳細を表示
  function renderNetworkDetails() {
    const panel = document.getElementById('network-panel');
    if (!panel || !dtSelectedRequest) return;

    const detailsPanel = panel.querySelector('.dt-network-details');
    detailsPanel.innerHTML = '';

    // 一般情報
    const generalSection = document.createElement('div');
    generalSection.className = 'dt-network-detail-section';
    generalSection.innerHTML = `
      <div class="dt-network-detail-title">一般</div>
      <div class="dt-network-detail-content">
        <strong>URL:</strong> ${dtSelectedRequest.url}<br>
        <strong>メソッド:</strong> ${dtSelectedRequest.method}<br>
        <strong>ステータス:</strong> ${dtSelectedRequest.response ? dtSelectedRequest.response.status : '-'}<br>
        <strong>時間:</strong> ${dtSelectedRequest.duration ? Math.round(dtSelectedRequest.duration) + 'ms' : '-'}
      </div>
    `;
    detailsPanel.appendChild(generalSection);

    // リクエストヘッダー
    if (dtSelectedRequest.requestHeaders) {
      const headersSection = document.createElement('div');
      headersSection.className = 'dt-network-detail-section';
      
      const headersTitle = document.createElement('div');
      headersTitle.className = 'dt-network-detail-title';
      headersTitle.textContent = 'リクエストヘッダー';
      
      const headersContent = document.createElement('div');
      headersContent.className = 'dt-network-detail-content';
      
      if (typeof dtSelectedRequest.requestHeaders === 'object' && !(dtSelectedRequest.requestHeaders instanceof Headers)) {
        Object.entries(dtSelectedRequest.requestHeaders).forEach(([key, value]) => {
          headersContent.innerHTML += `<strong>${key}:</strong> ${value}<br>`;
        });
      } else if (dtSelectedRequest.requestHeaders instanceof Headers) {
        dtSelectedRequest.requestHeaders.forEach((value, key) => {
          headersContent.innerHTML += `<strong>${key}:</strong> ${value}<br>`;
        });
      }
      
      headersSection.appendChild(headersTitle);
      headersSection.appendChild(headersContent);
      detailsPanel.appendChild(headersSection);
    }

    // リクエストボディ
    if (dtSelectedRequest.requestBody) {
      const bodySection = document.createElement('div');
      bodySection.className = 'dt-network-detail-section';
      
      const bodyTitle = document.createElement('div');
      bodyTitle.className = 'dt-network-detail-title';
      bodyTitle.textContent = 'リクエストボディ';
      
      const bodyContent = document.createElement('div');
      bodyContent.className = 'dt-network-detail-content';
      
      try {
        if (typeof dtSelectedRequest.requestBody === 'string') {
          bodyContent.textContent = dtSelectedRequest.requestBody;
        } else if (typeof dtSelectedRequest.requestBody === 'object') {
          bodyContent.textContent = JSON.stringify(dtSelectedRequest.requestBody, null, 2);
        }
      } catch (e) {
        bodyContent.textContent = 'ボディを表示できません';
      }
      
      bodySection.appendChild(bodyTitle);
      bodySection.appendChild(bodyContent);
      detailsPanel.appendChild(bodySection);
    }

    // レスポンス
    if (dtSelectedRequest.response) {
      const responseSection = document.createElement('div');
      responseSection.className = 'dt-network-detail-section';
      
      const responseTitle = document.createElement('div');
      responseTitle.className = 'dt-network-detail-title';
      responseTitle.textContent = 'レスポンス';
      
      const responseContent = document.createElement('div');
      responseContent.className = 'dt-network-detail-content';
      
      if (dtSelectedRequest.response.body) {
        if (typeof dtSelectedRequest.response.body === 'object') {
          responseContent.textContent = JSON.stringify(dtSelectedRequest.response.body, null, 2);
        } else {
          responseContent.textContent = dtSelectedRequest.response.body;
        }
      } else {
        responseContent.textContent = 'レスポンスボディがありません';
      }
      
      responseSection.appendChild(responseTitle);
      responseSection.appendChild(responseContent);
      detailsPanel.appendChild(responseSection);
    }

    // エラー
    if (dtSelectedRequest.error) {
      const errorSection = document.createElement('div');
      errorSection.className = 'dt-network-detail-section';
      
      const errorTitle = document.createElement('div');
      errorTitle.className = 'dt-network-detail-title';
      errorTitle.textContent = 'エラー';
      
      const errorContent = document.createElement('div');
      errorContent.className = 'dt-network-detail-content';
      errorContent.textContent = `${dtSelectedRequest.error.name}: ${dtSelectedRequest.error.message}`;
      
      if (dtSelectedRequest.error.stack) {
        errorContent.innerHTML += `<br><br>${dtSelectedRequest.error.stack.replace(/\n/g, '<br>')}`;
      }
      
      errorSection.appendChild(errorTitle);
      errorSection.appendChild(errorContent);
      detailsPanel.appendChild(errorSection);
    }
  }

  // コンテキストメニュー作成
  function createContextMenu() {
    dtContextMenu = document.createElement('div');
    dtContextMenu.className = 'dt-context-menu';
    dtContextMenu.innerHTML = `
      <div class="dt-context-menu-item" data-action="edit-html">HTMLとして編集</div>
      <div class="dt-context-menu-item" data-action="edit-whole-html">HTML全体を編集</div>
      <div class="dt-context-menu-item" data-action="add-attribute">属性を追加</div>
      <div class="dt-context-menu-item" data-action="edit-element">要素を編集</div>
      <div class="dt-context-menu-item" data-action="duplicate">要素を複製</div>
      <div class="dt-context-menu-item" data-action="remove">要素を削除</div>
      <div class="dt-context-menu-item" data-action="toggle-visibility">要素を非表示</div>
      <div class="dt-context-menu-item" data-action="force-state">状態を強制</div>
    `;
    document.body.appendChild(dtContextMenu);

    dtContextMenu.querySelectorAll('.dt-context-menu-item').forEach(item => {
      item.addEventListener('click', (e) => {
        const action = e.target.getAttribute('data-action');
        handleContextMenuAction(action);
        dtContextMenu.style.display = 'none';
      });
    });

    document.addEventListener('click', (e) => {
      if (e.target !== dtContextMenu && !dtContextMenu.contains(e.target)) {
        dtContextMenu.style.display = 'none';
      }
    });
  }

  // Storageパネル作成
  function createStoragePanel() {
    const panel = document.createElement('div');
    panel.className = 'dt-devtools-panel';
    panel.id = 'storage-panel';

    // LocalStorage表示
    const localStorageTitle = document.createElement('h3');
    localStorageTitle.textContent = 'Local Storage';
    panel.appendChild(localStorageTitle);

    const localStorageTable = document.createElement('table');
    localStorageTable.className = 'dt-storage-table';
    panel.appendChild(localStorageTable);

    const addLocalStorageBtn = document.createElement('button');
    addLocalStorageBtn.className = 'dt-add-btn';
    addLocalStorageBtn.textContent = '+ Local Storageに追加';
    addLocalStorageBtn.onclick = () => {
      const key = prompt('キー名を入力');
      if (key) {
        const value = prompt('値を入力');
        localStorage.setItem(key, value);
        renderStorage();
      }
    };
    panel.appendChild(addLocalStorageBtn);

    // SessionStorage表示
    const sessionStorageTitle = document.createElement('h3');
    sessionStorageTitle.style.marginTop = '20px';
    sessionStorageTitle.textContent = 'Session Storage';
    panel.appendChild(sessionStorageTitle);

    const sessionStorageTable = document.createElement('table');
    sessionStorageTable.className = 'dt-storage-table';
    panel.appendChild(sessionStorageTable);

    const addSessionStorageBtn = document.createElement('button');
    addSessionStorageBtn.className = 'dt-add-btn';
    addSessionStorageBtn.textContent = '+ Session Storageに追加';
    addSessionStorageBtn.onclick = () => {
      const key = prompt('キー名を入力');
      if (key) {
        const value = prompt('値を入力');
        sessionStorage.setItem(key, value);
        renderStorage();
      }
    };
    panel.appendChild(addSessionStorageBtn);

    // Cookie表示
    const cookiesTitle = document.createElement('h3');
    cookiesTitle.style.marginTop = '20px';
    cookiesTitle.textContent = 'Cookies';
    panel.appendChild(cookiesTitle);

    const cookiesTable = document.createElement('table');
    cookiesTable.className = 'dt-storage-table';
    panel.appendChild(cookiesTable);

    const addCookieBtn = document.createElement('button');
    addCookieBtn.className = 'dt-add-btn';
    addCookieBtn.textContent = '+ Cookieに追加';
    addCookieBtn.onclick = () => {
      const name = prompt('Cookie名を入力');
      if (name) {
        const value = prompt('値を入力');
        document.cookie = `${encodeURIComponent(name)}=${encodeURIComponent(value)}; path=/`;
        renderStorage();
      }
    };
    panel.appendChild(addCookieBtn);

    // ストレージを表示する関数
    function renderStorage() {
      renderTable(localStorageTable, localStorage, 'local');
      renderTable(sessionStorageTable, sessionStorage, 'session');
      renderCookiesTable(cookiesTable);
    }

    function renderTable(tableElement, storage, type) {
      tableElement.innerHTML = `
        <thead>
          <tr>
            <th>Key</th>
            <th>Value</th>
            <th>Actions</th>
          </tr>
        </thead>
        <tbody></tbody>
      `;

      const tbody = tableElement.querySelector('tbody');
      
      for (let i = 0; i < storage.length; i++) {
        const key = storage.key(i);
        const value = storage.getItem(key);
        
        const row = document.createElement('tr');
        
        const keyCell = document.createElement('td');
        const keySpan = document.createElement('span');
        keySpan.className = 'dt-editable';
        keySpan.textContent = key;
        keySpan.onclick = () => {
          const newKey = prompt('新しいキー名を入力', key);
          if (newKey && newKey !== key) {
            storage.setItem(newKey, value);
            storage.removeItem(key);
            renderStorage();
          }
        };
        keyCell.appendChild(keySpan);
        
        const valueCell = document.createElement('td');
        const valueSpan = document.createElement('span');
        valueSpan.className = 'dt-editable';
        valueSpan.textContent = value;
        valueSpan.onclick = () => {
          const newValue = prompt('新しい値を入力', value);
          if (newValue !== null) {
            storage.setItem(key, newValue);
            renderStorage();
          }
        };
        valueCell.appendChild(valueSpan);
        
        const actionsCell = document.createElement('td');
        actionsCell.className = 'dt-storage-actions';
        
        const deleteBtn = document.createElement('button');
        deleteBtn.className = 'dt-storage-btn';
        deleteBtn.textContent = 'Delete';
        deleteBtn.onclick = () => {
          storage.removeItem(key);
          renderStorage();
        };
        
        actionsCell.appendChild(deleteBtn);
        
        row.appendChild(keyCell);
        row.appendChild(valueCell);
        row.appendChild(actionsCell);
        
        tbody.appendChild(row);
      }
    }

    function renderCookiesTable(tableElement) {
      tableElement.innerHTML = `
        <thead>
          <tr>
            <th>Name</th>
            <th>Value</th>
            <th>Actions</th>
          </tr>
        </thead>
        <tbody></tbody>
      `;

      const tbody = tableElement.querySelector('tbody');
      
      document.cookie.split(';').forEach(cookie => {
        if (!cookie.trim()) return;
        
        const [name, ...valueParts] = cookie.split('=');
        const decodedName = decodeURIComponent(name.trim());
        const value = valueParts.join('=').trim();
        
        const row = document.createElement('tr');
        
        const nameCell = document.createElement('td');
        const nameSpan = document.createElement('span');
        nameSpan.className = 'dt-editable';
        nameSpan.textContent = decodedName;
        nameSpan.onclick = () => {
          const newName = prompt('新しい名前を入力', decodedName);
          if (newName && newName !== decodedName) {
            const newValue = prompt('新しい値を入力', decodeURIComponent(value));
            if (newValue !== null) {
              document.cookie = `${encodeURIComponent(newName)}=${encodeURIComponent(newValue)}; expires=Fri, 31 Dec 9999 23:59:59 GMT; path=/`;
              document.cookie = `${name.trim()}=; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/`;
              renderStorage();
            }
          }
        };
        nameCell.appendChild(nameSpan);
        
        const valueCell = document.createElement('td');
        const valueSpan = document.createElement('span');
        valueSpan.className = 'dt-editable';
        valueSpan.textContent = decodeURIComponent(value);
        valueSpan.onclick = () => {
          const newValue = prompt('新しい値を入力', decodeURIComponent(value));
          if (newValue !== null) {
            document.cookie = `${name.trim()}=${encodeURIComponent(newValue)}; expires=Fri, 31 Dec 9999 23:59:59 GMT; path=/`;
            renderStorage();
          }
        };
        valueCell.appendChild(valueSpan);
        
        const actionsCell = document.createElement('td');
        actionsCell.className = 'dt-storage-actions';
        
        const deleteBtn = document.createElement('button');
        deleteBtn.className = 'dt-storage-btn';
        deleteBtn.textContent = 'Delete';
        deleteBtn.onclick = () => {
          document.cookie = `${name.trim()}=; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/`;
          renderStorage();
        };
        
        actionsCell.appendChild(deleteBtn);
        
        row.appendChild(nameCell);
        row.appendChild(valueCell);
        row.appendChild(actionsCell);
        
        tbody.appendChild(row);
      });
    }

    // 初期表示
    renderStorage();

    return panel;
  }

  // コンテキストメニューアクション処理
  function handleContextMenuAction(action) {
    if (!dtSelectedElement) return;

    switch (action) {
      case 'edit-html':
        if (dtSelectedElement === document.documentElement) {
          alert('ルートHTML要素は直接編集できません');
          return;
        }
        startInlineEdit(dtSelectedDOMNode, dtSelectedElement.outerHTML, (newValue) => {
          try {
            dtSelectedElement.outerHTML = newValue;
            dtRefreshElementsPanel();
          } catch (e) {
            alert('この要素は編集できません: ' + e.message);
          }
        });
        break;
      case 'edit-whole-html':
        const htmlContent = document.documentElement.outerHTML;
        const textarea = document.createElement('textarea');
        textarea.style.width = '100%';
        textarea.style.height = '300px';
        textarea.value = htmlContent;
        
        const modal = document.createElement('div');
        modal.style.position = 'fixed';
        modal.style.top = '0';
        modal.style.left = '0';
        modal.style.width = '100%';
        modal.style.height = '100%';
        modal.style.backgroundColor = 'rgba(0,0,0,0.8)';
        modal.style.zIndex = '10000';
        modal.style.display = 'flex';
        modal.style.flexDirection = 'column';
        modal.style.padding = '20px';
        modal.style.boxSizing = 'border-box';
        
        const buttonContainer = document.createElement('div');
        buttonContainer.style.marginTop = '10px';
        buttonContainer.style.display = 'flex';
        buttonContainer.style.gap = '10px';
        
        const saveButton = document.createElement('button');
        saveButton.textContent = '保存';
        saveButton.onclick = () => {
          try {
            document.documentElement.innerHTML = textarea.value;
            modal.remove();
            dtRefreshElementsPanel();
          } catch (e) {
            alert('HTMLの解析に失敗しました: ' + e.message);
          }
        };
        
        const cancelButton = document.createElement('button');
        cancelButton.textContent = 'キャンセル';
        cancelButton.onclick = () => {
          modal.remove();
        };
        
        buttonContainer.appendChild(saveButton);
        buttonContainer.appendChild(cancelButton);
        
        modal.appendChild(textarea);
        modal.appendChild(buttonContainer);
        
        document.body.appendChild(modal);
        break;
      case 'add-attribute':
        const attrName = prompt('属性名を入力');
        if (attrName) {
          const attrValue = prompt('属性値を入力');
          dtSelectedElement.setAttribute(attrName, attrValue || '');
          dtRefreshElementsPanel();
        }
        break;
      case 'edit-element':
        startInlineEdit(dtSelectedDOMNode.querySelector('.dt-dom-tag'), dtSelectedElement.tagName.toLowerCase(), (newValue) => {
          const newElement = document.createElement(newValue);
          Array.from(dtSelectedElement.attributes).forEach(attr => {
            newElement.setAttribute(attr.name, attr.value);
          });
          newElement.innerHTML = dtSelectedElement.innerHTML;
          dtSelectedElement.parentNode.replaceChild(newElement, dtSelectedElement);
          dtSelectedElement = newElement;
          dtRefreshElementsPanel();
        });
        break;
      case 'duplicate':
        const clone = dtSelectedElement.cloneNode(true);
        dtSelectedElement.parentNode.insertBefore(clone, dtSelectedElement.nextSibling);
        dtRefreshElementsPanel();
        break;
      case 'remove':
        if (confirm('要素を削除しますか？')) {
          dtSelectedElement.parentNode.removeChild(dtSelectedElement);
          dtRefreshElementsPanel();
        }
        break;
      case 'toggle-visibility':
        if (dtSelectedElement.style.display === 'none') {
          dtSelectedElement.style.display = '';
        } else {
          dtSelectedElement.style.display = 'none';
        }
        dtRefreshElementsPanel();
        break;
      case 'force-state':
        const state = prompt('強制する状態を入力 (例: hover, active, focus)', 'hover');
        if (state) {
          dtSelectedElement.classList.remove('force-hover', 'force-active', 'force-focus', 
                                        'force-focus-within', 'force-focus-visible', 'force-target');
          dtSelectedElement.classList.add(`force-${state}`);
          dtRefreshElementsPanel();
        }
        break;
    }
  }

  // インライン編集関数
  function startInlineEdit(element, initialValue, callback) {
    if (dtActiveEditElement) return;
    
    const originalValue = element.textContent;
    const rect = element.getBoundingClientRect();
    
    const input = document.createElement('input');
    input.className = 'dt-dom-edit-input';
    input.value = initialValue || originalValue;
    input.style.position = 'absolute';
    input.style.left = `${rect.left}px`;
    input.style.top = `${rect.top}px`;
    input.style.width = `${rect.width + 20}px`;
    
    document.body.appendChild(input);
    input.focus();
    input.select();
    
    dtActiveEditElement = {
      element: element,
      input: input,
      callback: callback
    };
    
    const clickOutsideHandler = (e) => {
      if (!input.contains(e.target)) {
        finishInlineEdit();
      }
    };
    
    input.addEventListener('keydown', (e) => {
      if (e.key === 'Enter') {
        finishInlineEdit();
      } else if (e.key === 'Escape') {
        cancelInlineEdit();
      }
    });
    
    setTimeout(() => {
      document.addEventListener('click', clickOutsideHandler);
    }, 0);
    
    function finishInlineEdit() {
      try {
        if (input.value !== originalValue && callback) {
          callback(input.value);
        }
      } catch (e) {
        alert('編集に失敗しました: ' + e.message);
      } finally {
        cleanup();
      }
    }
    
    function cancelInlineEdit() {
      cleanup();
    }
    
    function cleanup() {
      document.removeEventListener('click', clickOutsideHandler);
      input.remove();
      dtActiveEditElement = null;
    }
  }

  // Consoleパネル作成
  function createConsolePanel() {
    const panel = document.createElement('div');
    panel.className = 'dt-devtools-panel';
    panel.id = 'console-panel';

    const log = document.createElement('div');
    log.id = 'dt-console-log';

    const input = document.createElement('input');
    input.className = 'dt-console-input';
    input.placeholder = 'ここにJavaScriptを入力... (Enterで実行)';
    input.onkeypress = (e) => {
      if (e.key === 'Enter') {
        try {
          const result = eval(e.target.value);
          if (result !== undefined) {
            logMessage('> ' + e.target.value, 'dt-console-log');
            logMessage('← ' + formatOutput(result), 'dt-console-log');
          }
        } catch (err) {
          logMessage(err.message, 'dt-console-error');
        }
        e.target.value = '';
      }
    };

    panel.appendChild(log);
    panel.appendChild(input);

    // コンソールメソッドをオーバーライド
    const originalConsole = {
      log: console.log,
      error: console.error,
      warn: console.warn,
      info: console.info
    };

    console.log = (...args) => {
      originalConsole.log.apply(console, args);
      logMessage(args.map(arg => formatOutput(arg)).join(' '), 'dt-console-log');
    };

    console.error = (...args) => {
      originalConsole.error.apply(console, args);
      logMessage(args.map(arg => formatOutput(arg)).join(' '), 'dt-console-error');
    };

    console.warn = (...args) => {
      originalConsole.warn.apply(console, args);
      logMessage(args.map(arg => formatOutput(arg)).join(' '), 'dt-console-warn');
    };

    console.info = (...args) => {
      originalConsole.info.apply(console, args);
      logMessage(args.map(arg => formatOutput(arg)).join(' '), 'dt-console-info');
    };

    function logMessage(message, className) {
      const line = document.createElement('div');
      line.className = className;
      line.innerHTML = message;
      log.appendChild(line);
      log.scrollTop = log.scrollHeight;
    }

    function formatOutput(output) {
      if (output === null) return '<span class="dt-json-null">null</span>';
      if (output === undefined) return '<span class="dt-json-null">undefined</span>';
      if (typeof output === 'boolean') return `<span class="dt-json-boolean">${output}</span>`;
      if (typeof output === 'number') return `<span class="dt-json-number">${output}</span>`;
      if (typeof output === 'string') return `<span class="dt-json-string">"${output}"</span>`;
      if (typeof output === 'function') return `<span class="dt-json-object">function ${output.name}() { ... }</span>`;
      if (Array.isArray(output)) return `<span class="dt-json-object">[${output.map(formatOutput).join(', ')}]</span>`;
      if (typeof output === 'object') {
        try {
          return `<span class="dt-json-object">${JSON.stringify(output, null, 2)
            .replace(/"([^"]+)":/g, '<span class="dt-json-key">"$1"</span>:')
            .replace(/"([^"]+)"/g, '<span class="dt-json-string">"$1"</span>')
            .replace(/\b(true|false)\b/g, '<span class="dt-json-boolean">$1</span>')
            .replace(/\b(null)\b/g, '<span class="dt-json-null">$1</span>')
            .replace(/\b(\d+)\b/g, '<span class="dt-json-number">$1</span>')}</span>`;
        } catch (e) {
          return `<span class="dt-json-object">${output.toString()}</span>`;
        }
      }
      return output;
    }

    return panel;
  }

  // Elementsパネル作成
  function createElementsPanel() {
    const panel = document.createElement('div');
    panel.className = 'dt-devtools-panel';
    panel.id = 'elements-panel';

    const container = document.createElement('div');
    container.className = 'dt-elements-container';

    const tree = document.createElement('div');
    tree.className = 'dt-dom-tree';
    tree.id = 'dt-dom-tree';

    const cssPanel = document.createElement('div');
    cssPanel.className = 'dt-css-panel';
    cssPanel.id = 'dt-css-panel';

    container.appendChild(tree);
    container.appendChild(cssPanel);
    panel.appendChild(container);

    // CSSパネル更新関数
    function updateCSSPanel(element) {
      const cssPanel = document.getElementById('dt-css-panel');
      cssPanel.innerHTML = '';
      
      if (!element) return;
      
      if (element.style.length > 0) {
        const inlineRule = document.createElement('div');
        inlineRule.className = 'dt-css-rule';
        
        const selector = document.createElement('div');
        selector.className = 'dt-css-selector';
        selector.textContent = 'インラインスタイル';
        inlineRule.appendChild(selector);
        
        for (let i = 0; i < element.style.length; i++) {
          const propName = element.style[i];
          const propValue = element.style[propName];
          
          const propDiv = document.createElement('div');
          propDiv.className = 'dt-css-property';
          
          const nameSpan = document.createElement('span');
          nameSpan.className = 'dt-css-property-name dt-editable';
          nameSpan.textContent = propName;
          nameSpan.onclick = () => editCSSProperty(element, propName, 'style');
          
          const valueSpan = document.createElement('span');
          valueSpan.className = 'dt-css-property-value dt-editable';
          valueSpan.textContent = propValue;
          valueSpan.onclick = () => editCSSProperty(element, propName, 'style');
          
          const toggleSpan = document.createElement('span');
          toggleSpan.className = 'dt-css-toggle';
          toggleSpan.textContent = '×';
          toggleSpan.title = 'プロパティを無効化';
          toggleSpan.onclick = () => {
            element.style[propName] = '';
            updateCSSPanel(element);
          };
          
          propDiv.appendChild(nameSpan);
          propDiv.appendChild(valueSpan);
          propDiv.appendChild(toggleSpan);
          inlineRule.appendChild(propDiv);
        }
        
        cssPanel.appendChild(inlineRule);
      }
      
      const computedStyles = window.getComputedStyle(element);
      const computedRule = document.createElement('div');
      computedRule.className = 'dt-css-rule';
      
      const computedSelector = document.createElement('div');
      computedSelector.className = 'dt-css-selector';
      computedSelector.textContent = '計算されたスタイル';
      computedRule.appendChild(computedSelector);
      
      const importantProps = [
        'display', 'position', 'width', 'height', 'margin', 'padding', 
        'color', 'background', 'border', 'font', 'flex', 'grid'
      ];
      
      importantProps.forEach(prop => {
        const value = computedStyles[prop];
        
        const propDiv = document.createElement('div');
        propDiv.className = 'dt-css-property';
        
        const nameSpan = document.createElement('span');
        nameSpan.className = 'dt-css-property-name';
        nameSpan.textContent = prop;
        
        const valueSpan = document.createElement('span');
        valueSpan.className = 'dt-css-property-value';
        valueSpan.textContent = value;
        
        propDiv.appendChild(nameSpan);
        propDiv.appendChild(valueSpan);
        computedRule.appendChild(propDiv);
      });
      
      cssPanel.appendChild(computedRule);
    }

    // DOMツリー構築
    function buildDOMTree(node, parentElement, depth = 0, isRoot = false) {
      if (node.nodeType === Node.ELEMENT_NODE) {
        const element = document.createElement('div');
        element.className = 'dt-dom-node';
        element.style.marginLeft = `${depth * 15}px`;
        element.dataset.elementId = node.id || Math.random().toString(36).substr(2, 9);

        // 右クリックイベント
        element.oncontextmenu = (e) => {
          e.preventDefault();
          dtSelectedElement = node;
          dtSelectedDOMNode = element;
          
          document.querySelectorAll('.dt-dom-node').forEach(el => el.classList.remove('selected'));
          element.classList.add('selected');
          
          if (node !== document.documentElement) {
            dtContextMenu.style.display = 'block';
            dtContextMenu.style.left = `${e.pageX}px`;
            dtContextMenu.style.top = `${e.pageY}px`;
          }
          
          updateCSSPanel(node);
        };

        // 左クリックで選択
        element.onclick = (e) => {
          if (e.target.classList.contains('dt-dom-toggle')) return;
          
          e.stopPropagation();
          dtSelectedElement = node;
          dtSelectedDOMNode = element;
          
          document.querySelectorAll('.dt-dom-node').forEach(el => el.classList.remove('selected'));
          element.classList.add('selected');
          
          updateCSSPanel(node);
        };

        // 子要素がある場合はトグルボタンを追加
        const hasChildren = node.childNodes.length > 0 && 
                          !(node.childNodes.length === 1 && node.childNodes[0].nodeType === Node.TEXT_NODE && !node.childNodes[0].textContent.trim());
        
        if (hasChildren) {
          const toggle = document.createElement('div');
          toggle.className = 'dt-dom-toggle';
          toggle.onclick = (e) => {
            e.stopPropagation();
            const children = element.querySelector('.dt-dom-children');
            if (children) {
              if (children.style.maxHeight === '0px') {
                children.style.maxHeight = children.scrollHeight + 'px';
                toggle.classList.remove('collapsed');
              } else {
                children.style.maxHeight = '0px';
                toggle.classList.add('collapsed');
              }
            }
          };
          element.appendChild(toggle);
        }

        // タグ名（HTML要素は編集不可）
        const tag = document.createElement('span');
        tag.className = 'dt-dom-tag';
        tag.textContent = `<${node.tagName.toLowerCase()}`;
        
        if (node !== document.documentElement) {
          tag.classList.add('dt-editable');
          tag.onclick = (e) => {
            e.stopPropagation();
            startInlineEdit(tag, node.tagName.toLowerCase(), (newValue) => {
              const newElement = document.createElement(newValue);
              Array.from(node.attributes).forEach(attr => {
                newElement.setAttribute(attr.name, attr.value);
              });
              newElement.innerHTML = node.innerHTML;
              node.parentNode.replaceChild(newElement, node);
              dtSelectedElement = newElement;
              dtRefreshElementsPanel();
            });
          };
        }
        
        element.appendChild(tag);

        // 属性（HTML要素は編集不可）
        Array.from(node.attributes).forEach(attr => {
          const attrSpan = document.createElement('span');
          attrSpan.className = 'dt-dom-attr';
          attrSpan.textContent = ` ${attr.name}="${attr.value}"`;
          
          if (node !== document.documentElement) {
            attrSpan.classList.add('dt-editable');
            attrSpan.onclick = (e) => {
              e.stopPropagation();
              startInlineEdit(attrSpan, attr.value, (newValue) => {
                node.setAttribute(attr.name, newValue);
                dtRefreshElementsPanel();
              });
            };
          }
          
          element.appendChild(attrSpan);
        });

        element.appendChild(document.createTextNode('>'));

        if (hasChildren) {
          const childrenContainer = document.createElement('div');
          childrenContainer.className = 'dt-dom-children';
          childrenContainer.style.maxHeight = isRoot ? 'none' : '0px';
          
          node.childNodes.forEach(child => {
            buildDOMTree(child, childrenContainer, depth + 1);
          });

          if (node.tagName.toLowerCase() !== 'br') {
            const closeTag = document.createElement('div');
            closeTag.style.marginLeft = `${depth * 15}px`;
            closeTag.innerHTML = `<span class="dt-dom-tag">&lt;/${node.tagName.toLowerCase()}&gt;</span>`;
            childrenContainer.appendChild(closeTag);
          }
          
          element.appendChild(childrenContainer);
        }

        parentElement.appendChild(element);
      } else if (node.nodeType === Node.TEXT_NODE && node.textContent.trim()) {
        const text = document.createElement('div');
        text.style.marginLeft = `${depth * 15}px`;
        text.className = 'dt-dom-text dt-editable';
        text.textContent = `"${node.textContent.trim()}"`;
        text.onclick = (e) => {
          e.stopPropagation();
          startInlineEdit(text, node.textContent.trim(), (newValue) => {
            node.textContent = newValue;
            dtRefreshElementsPanel();
          });
        };
        parentElement.appendChild(text);
      }
    }

    // CSSプロパティ編集
    function editCSSProperty(element, propName, styleType) {
      let currentValue = '';
      
      if (styleType === 'style') {
        currentValue = element.style[propName];
      }
      
      const newValue = prompt(`${propName} の新しい値を入力`, currentValue);
      
      if (newValue !== null) {
        if (styleType === 'style') {
          element.style[propName] = newValue;
        }
        
        updateCSSPanel(element);
        dtRefreshElementsPanel();
      }
    }

let isRefreshing = false;
dtRefreshElementsPanel = function() {
  if (isRefreshing) return;
  isRefreshing = true;
  
  requestAnimationFrame(() => {
    let tree = document.getElementById('dt-dom-tree');
    tree.innerHTML = '';
    buildDOMTree(document.documentElement, tree, 0, true);
    isRefreshing = false;
  });
};
    // MutationObserverの設定
    setupMutationObserver();

    // 初期表示
    setTimeout(() => {
      dtRefreshElementsPanel();
    }, 0);

    return panel;
  }

  // 開発者ツール表示/非表示
  function toggleDevTools() {
    const container = document.getElementById('dt-devtools-container');
    if (container.style.display === 'none') {
      container.style.display = 'flex';
    } else {
      container.style.display = 'none';
    }
  }

  // 開くボタン作成
  function createOpenButton() {
    const button = document.createElement('button');
    button.id = 'dt-open-devtools-btn';
    button.textContent = '開発者ツールを開く';
    button.style.position = 'fixed';
    button.style.bottom = '10px';
    button.style.right = '10px';
    button.style.padding = '8px 16px';
    button.style.background = 'var(--dt-primary-color)';
    button.style.color = '#000';
    button.style.border = 'none';
    button.style.borderRadius = '4px';
    button.style.cursor = 'pointer';
    button.style.zIndex = '9998';
    button.onclick = toggleDevTools;

    document.body.appendChild(button);
  }

  // 初期化
  document.addEventListener('DOMContentLoaded', function() {
    // 最小限のUIだけ先に表示
    createOpenButton();
    
    // メインのツールは遅延読み込み
    setTimeout(() => {
      createDevTools();
      console.log('開発者ツールが初期化されました');
    }, 1000);
  });
})();