diff --git a/app.py b/app.py
index a2c4176..119fbeb 100644
--- a/app.py
+++ b/app.py
@@ -626,22 +626,15 @@ class FeedbackClassifyRequest(BaseModel):
 
 
 
-
-
-
-def _citation_display_filename(
-    value: Any,
-    file_id: Any = "",
-) -> Any:
+def _citation_display_filename(value: Any) -> Any:
     """仅转换文本溯源展示名，不修改 file_id 或实际文件路径。"""
     if not isinstance(value, str):
         return value
-    if not re.search(r"(?i)\.(?:pptx|ppt)$", value.strip()):
-        return value
-    normalized_file_id = str(file_id or "").strip()
-    if not normalized_file_id:
-        return value
-    return f"{normalized_file_id}.pdf"
+    return re.sub(
+        r"(?i)\.(?:pptx|ppt)$",
+        ".pdf",
+        value.strip(),
+    )
 
 
 def normalize_source_citation_filenames(
@@ -653,20 +646,7 @@ def normalize_source_citation_filenames(
 
     normalized: Dict[str, Any] = {}
     for resource_name, items in source_citation.items():
-        group_file_id = ""
-        if isinstance(items, list):
-            group_file_id = next(
-                (
-                    item.get("file_id")
-                    for item in items
-                    if isinstance(item, dict) and item.get("file_id")
-                ),
-                "",
-            )
-        display_resource = _citation_display_filename(
-            resource_name,
-            group_file_id,
-        )
+        display_resource = _citation_display_filename(resource_name)
 
         if isinstance(items, list):
             normalized_items = []
@@ -675,12 +655,10 @@ def normalize_source_citation_filenames(
                     normalized_items.append(item)
                     continue
                 normalized_item = dict(item)
-                item_file_id = normalized_item.get("file_id") or group_file_id
                 for field in ("filename", "resource", "title"):
                     if field in normalized_item:
                         normalized_item[field] = _citation_display_filename(
-                            normalized_item[field],
-                            item_file_id,
+                            normalized_item[field]
                         )
                 normalized_items.append(normalized_item)
         else:
@@ -699,6 +677,7 @@ def normalize_source_citation_filenames(
     return normalized
 
 
+
 def format_stream_event(event_type: str,
                         data: Dict[str, Any],
                         chat_id: str = "",