fix a bug

app.py

@@ -215,7 +215,7 @@ def call_gemini(topic: str, level: str, difficulty: int) -> str:
 
     client = genai.Client(api_key=GEMINI_API_KEY)
     response = client.models.generate_content(
-        model="gemini-2.0-flash",   # ← fixed: was "gemini-1.5-flash" (404)
+        model="gemini-2.0-flash",
         contents=build_user_prompt(topic, level, difficulty),
         config=types.GenerateContentConfig(
             system_instruction=SYSTEM_PROMPT,
@@ -502,7 +502,7 @@ body, .gradio-container {
 footer { display: none !important; }
 """
 
-with gr.Blocks(title="Prompt2Project", css=CSS, theme=gr.themes.Base()) as demo:
+with gr.Blocks(title="Prompt2Project", theme=gr.themes.Base()) as demo:
 
     # ── Header ──────────────────────────────────────────────────────────────
     gr.HTML("""
@@ -564,4 +564,4 @@ with gr.Blocks(title="Prompt2Project", css=CSS, theme=gr.themes.Base()) as demo:
     )
 
 if __name__ == "__main__":
-    demo.launch()
+    demo.launch(css=CSS)