Update app.py

app.py

@@ -1,5 +1,23 @@
 import streamlit as st
 
+st.markdown(
+"""
+<style>
+
+.stApp{
+background-image: url("https://images.unsplash.com/photo-1554284126-aa88f22d8b74");
+background-size: cover;
+}
+
+h1{
+color:white;
+text-align:center;
+}
+
+</style>
+""",
+unsafe_allow_html=True
+)
 if "logged_in" not in st.session_state:
     st.session_state.logged_in = False
 
@@ -10,6 +28,10 @@ if not st.session_state.logged_in:
 sys.path.append(os.path.abspath("../model"))
 sys.path.append(os.path.abspath("../prompt"))
 
+if st.button("Logout"):
+    st.session_state.logged_in = False
+    st.experimental_rerun()
+
 # ---------- IMPORT YOUR FILES ----------
 from model_api import query_model
 from prompt_builder import build_prompt, calculate_bmi, bmi_category