Update app.py

app.py

@@ -17,14 +17,22 @@ STEPFUN_LOGO_PATH = "/tmp/stepfun_logo.svg"
 
 def download_logo():
     """下载 StepFun logo 到本地"""
-    if not os.path.exists(STEPFUN_LOGO_PATH):
-        try:
-            response = httpx.get(STEPFUN_LOGO_URL, timeout=10.0)
-            if response.status_code == 200:
-                with open(STEPFUN_LOGO_PATH, "wb") as f:
-                    f.write(response.content)
-        except:
-            pass
+    try:
+        response = httpx.get(STEPFUN_LOGO_URL, timeout=10.0, follow_redirects=True)
+        if response.status_code == 200:
+            with open(STEPFUN_LOGO_PATH, "wb") as f:
+                f.write(response.content)
+            return True
+    except Exception:
+        pass
+    return False
+
+
+def get_assistant_avatar():
+    """获取助手头像，优先使用下载的 logo，失败则用 emoji"""
+    if os.path.exists(STEPFUN_LOGO_PATH):
+        return STEPFUN_LOGO_PATH
+    return "🚀"
 
 
 # 启动时下载 logo
@@ -194,7 +202,7 @@ def main():
             with st.chat_message("user"):
                 st.markdown(msg["content"])
         elif msg["role"] == "assistant":
-            with st.chat_message("assistant", avatar=STEPFUN_LOGO_PATH):
+            with st.chat_message("assistant", avatar=get_assistant_avatar()):
                 # 思考内容用 expander
                 if msg.get("thinking"):
                     render_thinking_expander(msg["thinking"], is_streaming=False)
@@ -230,7 +238,7 @@ def main():
             st.markdown(prompt)
 
         # 助手回复
-        with st.chat_message("assistant", avatar=STEPFUN_LOGO_PATH):
+        with st.chat_message("assistant", avatar=get_assistant_avatar()):
             # 思考内容占位符
             thinking_placeholder = st.empty()
             # 回答内容占位符