diff --git a/auto_reply.py b/auto_reply.py
index a9977eb..226bbf3 100644
--- a/auto_reply.py
+++ b/auto_reply.py
@@ -67,15 +67,19 @@ class AutoReply:
     def _get_answer(self, platform: str, msg: str, doc: dict, score: float) -> str or None:
         """提取答案 + 防重复检查。
         优先返回 doc['answer']（Q&A 段），兜底用整段 content。
+        非 Q&A 文档限制返回内容首 500 字符，避免子串匹配触发后返回整篇文件。
         """
-        answer = (doc.get("answer") or doc["content"]).strip()
+        answer = doc.get("answer")
+        if answer:
+            answer = answer.strip()
+        else:
+            # 非 Q&A 文档 → 取 content 前半段（最多 500 字符），不返回全文
+            content = doc.get("content", "").strip()
+            answer = content[:497] + "..." if len(content) > 500 else content
+
         if not answer:
             return None
 
-        # 截取过长内容
-        if len(answer) > 500:
-            answer = answer[:497] + "..."
-
         # 防重复指纹
         fp = hash(f"{platform}:{msg}:{answer[:80]}")
         replied_set = self._replied.setdefault(platform, set())
diff --git a/knowledge_base.py b/knowledge_base.py
index d9d5f78..bb9f029 100644
--- a/knowledge_base.py
+++ b/knowledge_base.py
@@ -151,11 +151,13 @@ class KnowledgeBase:
 
         # Fallback: 子串匹配（查询包含在文档标题或内容中）
         q = query.strip()
-        for doc in self.docs:
-            if q in doc["content"] or q in doc["title"]:
-                logger = logging.getLogger("msgbot.kb")
-                logger.debug(f"子串匹配: \"{q}\" → {doc['title']}")
-                return [(doc, min_score)]
+        # 短文本（<4 字符）不做子串匹配，避免"19:15""14:30"等时间戳误匹配 KB 文档
+        if len(q) >= 4:
+            for doc in self.docs:
+                if q in doc["content"] or q in doc["title"]:
+                    logger = logging.getLogger("msgbot.kb")
+                    logger.debug(f"子串匹配: \"{q}\" → {doc['title']}")
+                    return [(doc, min_score)]
         return results
 
     def get_doc_count(self) -> int:
diff --git a/main.py b/main.py
index 0dd0316..2f141f2 100644
--- a/main.py
+++ b/main.py
@@ -3,6 +3,7 @@
 import logging
 import os
 import sys
+import signal
 
 # 确保在项目目录
 os.chdir(os.path.dirname(os.path.abspath(__file__)))
@@ -42,6 +43,17 @@ def main():
         sys.exit(1)
 
     app = MsgBotApp()
+
+    # Ctrl+C 信号处理：Windows Tkinter mainloop 不响应 KeyboardInterrupt
+    # 需 signal handler 强制停止监控 + 退出
+    def _sigint_handler(sig, frame):
+        logger.info("收到 Ctrl+C，正在关闭...")
+        app.monitor.stop()
+        app.quit()
+        sys.exit(0)
+
+    signal.signal(signal.SIGINT, _sigint_handler)
+
     app.mainloop()
 
 
diff --git a/monitor.py b/monitor.py
index 376d2ed..7a6180c 100644
--- a/monitor.py
+++ b/monitor.py
@@ -16,7 +16,7 @@ import ctypes
 import difflib
 import os
 from datetime import datetime
-from concurrent.futures import ThreadPoolExecutor, TimeoutError as FuturesTimeout
+import signal
 from PIL import ImageGrab
 from winrt.windows.media.ocr import OcrEngine
 from winrt.windows.globalization import Language
@@ -212,6 +212,26 @@ class MessageMonitor:
                 pass
         return None
 
+    def _ensure_hwnd_with_timeout(self, platform: str, timeout: float = 12.0) -> Optional[int]:
+        """_ensure_hwnd 包装 daemon 线程超时保护。
+        
+        ThreadPoolExecutor 创建非 daemon 线程 → Ctrl+C 进程不退出。
+        改用 daemon thread + Event.wait(timeout)，daemon 线程不阻塞进程退出。
+        """
+        result = [None]
+        done = threading.Event()
+
+        def worker():
+            result[0] = self._ensure_hwnd(platform)
+            done.set()
+
+        t = threading.Thread(target=worker, daemon=True)
+        t.start()
+        if not done.wait(timeout=timeout):
+            logger.warning(f"[{platform}] _ensure_hwnd 超时({timeout:.0f}s)，跳过本轮")
+            return None
+        return result[0]
+
     # ── 强制刷新 UIA ──────────────────────────────────────────
 
     def _fresh_window(self, platform: str):
@@ -1411,16 +1431,7 @@ class MessageMonitor:
         self._poll_count[platform] = counter
 
         # 1. 确保窗口句柄（带超时保护，防止 UIA COM 调用挂死不返回）
-        hwnd = None
-        _ex = ThreadPoolExecutor(max_workers=1)
-        try:
-            hwnd = _ex.submit(self._ensure_hwnd, platform).result(timeout=12.0)
-        except FuturesTimeout:
-            logger.warning(f"[{platform}] _ensure_hwnd 超时(12s)，跳过本轮")
-        except Exception as e:
-            logger.warning(f"[{platform}] _ensure_hwnd 异常: {e}")
-        finally:
-            _ex.shutdown(wait=False)
+        hwnd = self._ensure_hwnd_with_timeout(platform, timeout=12.0)
         if not hwnd:
             if counter % 10 == 0:
                 logger.debug(f"[{platform}] 窗口未找到")
@@ -1499,6 +1510,14 @@ class MessageMonitor:
         MAX_NEW_ITEMS = 3
         new_items = new_items[:MAX_NEW_ITEMS]
 
+        # 过滤纯时间/日期文本 → 不应进入 KB 匹配（OCR 时间戳分割遗留的噪音片段）
+        # 这些文本在 KB 子串匹配阶段会命中文件内任何含相同数字的内容
+        new_items = [
+            it for it in new_items
+            if not re.match(r'^\d{1,2}[:：]\d{2}(?:[:：]\d{2})?$', it.strip())
+            and not re.match(r'^\d{4}[/-]\d{1,2}', it.strip())
+        ]
+
         # 更新 last_texts 与签名
         self._last_texts[platform] = list(texts)
         self._last_sig[platform] = sig
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