The article concludes that the cosmological fine-tuning problem has traditionally been parameter-centric, focusing on individual constants rather than the mathematical structure determining physical realizability. The paper proposes an alternative formulation based on Constraint Geometry, where the primary object is the system of interacting physical constraints governing cosmological admissibility. Within this framework, cosmological parameter space is a constrained geometric manifold, and the physically realizable universe is identified by membership within the Cosmological Viability Kernel, defined as the intersection of all feasible regions generated by these constraints. The authors introduce a unified mathematical formalism consisting of constraint operators, constraint hypersurfaces, feasible regions, viability kernels, normalized constraint margins, global viability margins, robustness functionals, and a derived Fine-Tuning Index. These objects transform fine-tuning into explicitly defined geometric quantities for rigorous mathematical analysis. A central conclusion is that fine-tuning is not a primitive property of parameters but an emergent consequence of the geometry of constrained parameter space. Apparent parameter sensitivity arises when the viability kernel possesses narrow margins, restrictive intersections, highly curved boundaries, or other geometric features that reduce the neighborhood of admissible configurations. Conversely, cosmological models located deep within broad viable regions exhibit intrinsic robustness without requiring exceptional parameter adjustment. Fine-tuning is thus reinterpreted as a derived geometric phenomenon rather than an independent explanatory principle.