The present work develops a variational account of gravitational phenomena based on a closed quartic functional framework. Starting from a universal functional and its stationary condition, the admissible configuration space is constructed explicitly, together with the associated Hessian operator and its spectral structure. Within this framework, long-range interaction is not introduced as a fundamental force, but emerges from the quartic coupling term as an effective kernel with asymptotic behavior proportional to the inverse radial distance. The resulting dynamics reproduces inverse-square radial evolution, orbital stability, and Keplerian motion without postulating gravitational interaction or spacetime geometry. Physical evolution is interpreted as a transition between admissible configurations selected by a global criterion. In this sense, the phenomenon commonly described as gravitational fall is reinterpreted as structural reconfiguration rather than force-driven motion. The same variational structure extends to large-scale systems, providing a unified account of orbital dynamics and galactic rotation without introducing additional entities. The results suggest that gravitational phenomena are not fundamental but arise from an underlying generative variational structure that is closed, non-modular, and internally determined.
