fix: Gradio 6.0 compatibility — move css to launch(), remove Chatbot type arg

app.py

@@ -270,7 +270,7 @@ footer { display: none !important; }
 # UI
 # ─────────────────────────────────────────────────────────────────────────────
 
-with gr.Blocks(title="Kerdos AI — Custom LLM Chat | Document Q&A Demo", css=CSS) as demo:
+with gr.Blocks(title="Kerdos AI — Custom LLM Chat | Document Q&A Demo") as demo:
 
     # ── Kerdos Header ────────────────────────────────────────────────────────
     gr.HTML("""
@@ -369,7 +369,7 @@ with gr.Blocks(title="Kerdos AI — Custom LLM Chat | Document Q&A Demo", css=CS
         # ── Right panel: Chat ─────────────────────────────────────────────────
         with gr.Column(scale=2):
             gr.Markdown("### 💬 Ask Questions")
-            chatbot = gr.Chatbot(height=420, show_label=False, type="messages")
+            chatbot = gr.Chatbot(height=420, show_label=False)
 
             with gr.Row():
                 user_input = gr.Textbox(
@@ -457,4 +457,4 @@ with gr.Blocks(title="Kerdos AI — Custom LLM Chat | Document Q&A Demo", css=CS
 
 if __name__ == "__main__":
     demo.queue()
-    demo.launch(theme=gr.themes.Soft())
+    demo.launch(theme=gr.themes.Soft(), css=CSS)