Gravity is not a fundamental force. It is the electromagnetic force after charge cancellation in neutral matter — the residual field that escapes because confinement is never perfect. The proton confines its energy through 18 eigenmode layers using 18 of the 120 vertices of the 600-cell. The remaining 102 vertices are not occupied. The fraction of electromagnetic energy that leaks through these unused vertices is the gravitational coupling αG = α¹⁸ × 12/7. No gravitational input is used. Gravity emerges from electromagnetism as a confinement exhaust product.