Update src/streamlit_app.py

src/streamlit_app.py

@@ -15,7 +15,7 @@ client = OpenAI(
 )
 
 #  style
-with open("src/theme.css") as f:
+with open("src/prompt_optimizer.css") as f:
     st.markdown(f"<style>{f.read()}</style>", unsafe_allow_html=True)
 
 # ------------------------