Update app.py

app.py

@@ -267,6 +267,7 @@ with gr.Blocks(title="Crack the Code") as demo:
             label="Still possible",
             info="Untick a digit to cross it off. This is only a note for you.",
             elem_id="marks",
+            interactive=True,  # outputs-only components default to read-only; this one is a personal notepad
         )
         with gr.Column(visible=True) as guess_row:
             guess_in = gr.Textbox(