I am not the person to explain, but this
article is very interesting and explains in easy terms CG range vs. stability. Read 6.1.1. through 6.1.6 at least.
Interesting read in 6.1.6, the author describes how a C172 at forward CG the tailplane produces downforce and at aft CG produces lift. This was apparently done by attaching strings on the tailplane and notice the direction of the vortices. In any case, the aircraft has static and dynamic stability (as one would expect within the CG range
)