Update app.py

app.py

@@ -78,8 +78,8 @@ css = """
     border-radius: 8px;
   }
   #run_button {
-    background-color: #000000; /* Dark button color */
-    color: white; /* White text */
+    background-color: #ffffff; 
+    color: black; /* White text */
     border-radius: 10px;
     padding: 10px;
     cursor: pointer;