The solution from this question did not work for me. And another answer suggests that firebase deploy does not overwrite the same CSS file. I'm able to deploy a new CSS file with a new name. But I'd like to keep the same CSS file, make changes, and deploy it again. Would this be possible?
All files that have changes will be deployed. The changes are detected by the checksum.
The name doesn't matter. As James More wrote on his comment here:
now is "will only deploy files with different checksums".
Do you experience a behaviour other than that? One thing you should consider is the CSS Cache in Browsers. It can get very tricky. Even when you update the CSS the Page shows the old one.