diff --git a/preload.js b/preload.js
index af52ab3..ac4d16f 100644
--- a/preload.js
+++ b/preload.js
@@ -22,13 +22,11 @@ contextBridge.exposeInMainWorld('electronAPI', {
 
   // Events from main process
   onFileOpenInTab: (callback) => ipcRenderer.on('file:openInTab', (event, data) => callback(data)),
-  onFileOpened: (callback) => ipcRenderer.on('file:opened', (event, data) => callback(data)),
   onMenuSave: (callback) => ipcRenderer.on('menu:save', () => callback()),
   onMenuSaveAs: (callback) => ipcRenderer.on('menu:saveAs', () => callback()),
   onViewModeChange: (callback) => ipcRenderer.on('menu:viewMode', (event, mode) => callback(mode)),
   onExternalModification: (callback) => ipcRenderer.on('file:externallyModified', (event, filePath) => callback(filePath)),
   onConfirmClose: (callback) => ipcRenderer.on('window:confirmClose', () => callback()),
-  onClosing: (callback) => ipcRenderer.on('window:closing', () => callback()),
 
   // Remove listeners
   removeAllListeners: (channel) => ipcRenderer.removeAllListeners(channel)
diff --git a/renderer/renderer.js b/renderer/renderer.js
index 1e4b010..0a86d10 100644
--- a/renderer/renderer.js
+++ b/renderer/renderer.js
@@ -120,13 +120,15 @@
   // ===== Markdown Rendering =====
   function renderMarkdown(text) {
     if (typeof marked === 'undefined') {
-      preview.innerHTML = '<p style="color: red;">错误: Markdown 解析库未加载</p>';
+      preview.textContent = '错误: Markdown 解析库未加载';
+      preview.style.color = 'red';
       return;
     }
     try {
       preview.innerHTML = marked.parse(text);
     } catch (e) {
-      preview.innerHTML = '<p style="color: red;">渲染错误: ' + e.message + '</p>';
+      preview.textContent = '渲染错误: ' + e.message;
+      preview.style.color = 'red';
     }
   }
 
@@ -468,7 +470,7 @@
       a.href = URL.createObjectURL(blob);
       a.download = tab.filePath || 'untitled.md';
       a.click();
-      URL.revokeObjectURL(a.href);
+      setTimeout(() => URL.revokeObjectURL(a.href), 1000);
       tab.isModified = false;
       renderTabBar();
       updateTitle();
@@ -739,7 +741,6 @@
     if (typeof window.electronAPI !== 'undefined') {
       // Remove old listeners first to prevent stacking
       window.electronAPI.removeAllListeners('file:openInTab');
-      window.electronAPI.removeAllListeners('file:opened');
       window.electronAPI.removeAllListeners('menu:save');
       window.electronAPI.removeAllListeners('menu:saveAs');
       window.electronAPI.removeAllListeners('menu:viewMode');
@@ -749,11 +750,6 @@
         createNewTab(data.filePath, data.content);
       });
 
-      // Legacy: file opened via old dialog
-      window.electronAPI.onFileOpened((data) => {
-        createNewTab(data.filePath, data.content);
-      });
-
       window.electronAPI.onMenuSave(() => handleSave());
       window.electronAPI.onMenuSaveAs(() => handleSaveAs());
       window.electronAPI.onViewModeChange((mode) => setViewMode(mode));