fix: banner移入content-wrapper，标签栏下方直接是两栏布局

renderer/renderer.js

@@ -17,6 +17,7 @@
   const editorPanel = document.getElementById('editor-panel');
   const previewPanel = document.getElementById('preview-panel');
   const mainContent = document.getElementById('main-content');
+  const contentWrapper = document.getElementById('content-wrapper');
   const tabList = document.getElementById('tab-list');
 
   // Sidebar
@@ -822,7 +823,7 @@
 
     document.addEventListener('mousemove', (e) => {
       if (!isResizing) return;
-      const rect = mainContent.getBoundingClientRect();
+      const rect = contentWrapper.getBoundingClientRect();
       const pct = Math.max(20, Math.min(80, ((e.clientX - rect.left) / rect.width) * 100));
       editorPanel.style.flex = `0 0 ${pct}%`;
       previewPanel.style.flex = `0 0 ${100 - pct}%`;