My study is being redecorated after the need to dig under the floor to
replace the incoming water main. I am refitting the fitted bookcases
across one wall and I have a wire in place to add some lighting. I want
lights behind the cornice of the bookcases shining onto the ceiling for
a nice gentle dffused effect.

In the few years since I last looked everything has gone LED and I have
no idea what kind of fitting I need. An LED cord? A batten? or battens?
In the olden days you might have used fluorescent tubes, but not now.
The bookcase is all of one wall, 2.5m wide and the cornice is about
300mm below the ceiling. I have some foil tape to make it all reflective.

What sort of light is needed in this situation?

TW