Maybe something like "goodnight handsome," if it is a guy and you like him. If it is someone you don't like or don't want to encourage, "bye" works.
Beautiful by Akon
Jó éjszakát és szép álmokat.
belle nuit
Something along the lines of "Thy night was quaint? I do presume, fair maiden."
In Telugu, to say "good night" you would say "శుభరాత్రి" (shubharatri).
If she texted you back then that is a good sign. But if she don't text you back then that may be a sign of cheating. You may want to ask her do you want to have dinner then have her spend the night.... It really did work for me no lie!
To say good night in Tagalog, you can say "Magandang gabi."
good night in samoa
A response when someone says good night is to say good night to you too.
You can say "good night" in Malayalam as "shubharathri."
You can (try to) say Yá'át'ééh hiiłchi'į'
To say "good night dad" in French, say Bonne nuit, papa.