/* ─── Mobile Nav Overlay ─── */
.nav-overlay {
    position: fixed;
    inset: 0;
    background: rgba(10,37,64,0.4);
    z-index: 99;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
}
.nav-overlay.active { opacity: 1; pointer-events: all; }