How do you use the bundle in the CLI ?

[A-Lamia]

Hey,
I'm unsure how to use the bundle feature, tried using @import 'a.css' in main.css then running
lightningcss --bundle ./src/main.css ./main.css, this didn't work, so i tried some stuff i found in
git issues but that just took multiple inputs and gave multiple outputs.

Not sure if what i want is possible or if I'm doing something wrong any help would be appreciated.

Thanks.