Hotfix, because Python f-strings aren't (yet) full Python

app.py

@@ -92,7 +92,7 @@ for span in spans:
 html_out = ''
 for span in spans:
     is_different = span['token'] != span['most_likely_token']
-    html_out += f'<span style="color: {'red' if is_different else 'black'}" title="{html.escape(span["most_likely_token"])}">{html.escape(span["token"])}</span>'
+    html_out += f'<span style="color: {"red" if is_different else "black"}" title="{html.escape(span["most_likely_token"])}">{html.escape(span["token"])}</span>'
 html_out = f"<p style=\"background: white;\">{html_out}</p>"
 
 st.subheader("Rewritten document")