Hi, the CG of airliners ( with tapered wings ) is called the CG of MAC
Mean Aerodynamic Chord. factory like Boeing establiswhes a datum line. the pitch axis of the aircraft. Then using a mathematical formula, they define the leading edge of MAC and the trailing edge of MAC of an equivalent straight wing. Then the factory defines a Neutral Point on that chord, They build a safety Margin in front of the NP - 5 to 15% of the MAC chord.
Then the factory establishes the empty weight CG, they also provide CG for various fuel load. - the CG creeps forward as the fuel burns in the wing tanks because of the shape.

The operator is responsible to load the aircraft within the CG of MAC
as established by the factory. i.e. from 12.5 to 35% of MAC

A low static margin from the NP, will make the aircraft tail heavy and susceptible to stall.
To much static margin  will make the aircraft nose heavy, reduces the effectiveness of the stab, and promotes very hard landing with a risk of stall at TO>

The factory provides all her numbers in the flight manual.

Happy flying ;D

Raymond   Boeing or nothing
KFLL  South florida