Perfect smart(/casual) backpack recommendation please?

[Siw2020]

I've spent weeks looking for a nice not too big and frumpy but big enough to fit the essentials (including A4 notepad, lunch, bottle of water, purse) backpack. Any suggestions?

Ideally black and leather with a laptop compartment but stylish too?
Soft leather rather than those hard firm ones.

lawfullondon.com/products/dahlia

this is the closest I have found - though it looks like quite hard leather and not sure I can quite justify spending £160 on a backpack even if I will use it everyday....

An external bottle compartment would be cool too but not essential