diff --git a/apps/desktop/src/renderer/src/components/SidePanel.tsx b/apps/desktop/src/renderer/src/components/SidePanel.tsx
index 043ac04..8013d40 100644
--- a/apps/desktop/src/renderer/src/components/SidePanel.tsx
+++ b/apps/desktop/src/renderer/src/components/SidePanel.tsx
@@ -70,18 +70,26 @@ export function SidePanel({
       onWidthChange(Math.min(PANEL_MAX_WIDTH, Math.max(PANEL_MIN_WIDTH, dragRef.current.startWidth + delta)))
     }
     const onUp = (): void => {
+      if (!dragRef.current) return
       dragRef.current = null
+      document.body.style.userSelect = ''
     }
     window.addEventListener('pointermove', onMove)
     window.addEventListener('pointerup', onUp)
     return () => {
       window.removeEventListener('pointermove', onMove)
       window.removeEventListener('pointerup', onUp)
+      document.body.style.userSelect = ''
     }
   }, [onWidthChange])
 
   const startResize = (e: React.PointerEvent): void => {
+    // preventDefault 必须在 pointerdown 上：否则 Chromium 会把它当作文本选择
+    // 手势的锚点，拖动经过聊天区/面板文字时把沿途内容选中；拖拽期间再对
+    // body 全局禁选（双保险，覆盖手势未被拦截的边缘情况），松手恢复
+    e.preventDefault()
     dragRef.current = { startX: e.clientX, startWidth: width }
+    document.body.style.userSelect = 'none'
   }
 
   // 菜单打开时 Esc 关闭