Update app.py

app.py

@@ -261,6 +261,9 @@ welcome_message = """
         0% { opacity: 0; }
         100% { opacity: 1; }
     }
+    body {
+        background-color: #dee9f7; /* Background color */
+    }
     #welcome-message {
         font-size: 2em;
         font-weight: bold;