It’s the leads module - so already the SuiteCRM 8 front-end.
I’d like to add some small CSS adjustments in the leads list & detail view.
Can you point me to a specific piece of documentation with CSS details?
All I can find is scss from Suite7.
Impossible to customize CSS in Suite 8 modules?
What changes are you trying to add in the Leads module?
The leads module is using angular front-end in suitecrm 8.x
It could be possible to move it to legacy mode, but you will not have version 8 features.