@media (max-width: 768px) {
    main {
        /* ocupa a tela toda menos a barra + safe area do iOS */
        min-height: calc(100svh - var(--h) - env(safe-area-inset-bottom));
        padding-bottom: calc(var(--h) + env(safe-area-inset-bottom));
        background-color: #f9f9f9;
    }
}


/* ====== Opcional: esconder no desktop ====== */
@media (min-width: 769px) {
    main {
        min-height: calc(100vh - 70px);
        padding-bottom: 70px;
        background-color: #f9f9f9;
    }
}