"Champagne is a sparkling French wine."
Translation:Le champagne est un vin français pétillant.
In English there is a rule (which native speakers know, but don't know that they know) about the ordering of adjectives: https://twitter.com/MattAndersonBBC/status/772002757222002688/
I tried to find similar rules in French and I think it is complex. The best link I have found is another Duolingo forum thread: https://forum.duolingo.com/comment/23574072/Is-there-a-particular-order-of-adjectives-in-French-I-don-t-mean-BAGS
Your English is better than the "rule"'s.
"French sparkling wine" 86, 400
"sparkling French wine" 21, 300
"vin pétillant français" 1, 120
"vin français pétillant" 72
It seems Duo's word order here is backwards in both languages. Both are accepted though (2020 June 19) -- my mistake was leaving out the "le" . . .
I wonder why they say champagne is masculine when the Larousse says its feminine https://www.larousse.fr/dictionnaires/francais/champagne/14561?q=champagne#14428