Despite decades of research, the origin of high-temperature superconductivity is still unclear, and its microscopic mechanism remains a subject of intense debate. The intrinsic Mott insulating properties of copper oxide parent compounds and the experimentally observed charge-ordered phases in real space suggest that high-temperature superconductivity may stem from localized electrons rather than itinerant electrons. In this work, we propose a unified microscopic mechanism where confined electrons within polyhedral quantum wells represent the Mott ground state, and symmetry-breaking of electron-hole pairs acts as the superconducting mechanism. A single parameter formula for the critical temperature (Tc) of unconventional superconductors is developed, allowing accurate determination of Tc based on lattice constants. The approach elucidates relationships between various charge-order phases and doping concentration, explores Fermi surface structures, investigates spin resonance peaks and parities, and examines pressure-induced dual superconducting phase transitions - all consistent with experimental observations. It is also estimated that the highest Tc of the newly discovered nickel-based superconductor will not exceed 100 K. This work offers critical insights into unconventional superconductivity’s fundamental mechanisms while introducing a new paradigm to reveal more intrinsic connections between superconductivity, conductivity, and magnetism.