.bg-fondo2 {
    background-image: linear-gradient( to bottom, rgba(0,0,0,0) 0%, /* Transparente arriba */
    rgba(0,0,0,0.3) 20%, /* Empieza el oscurecimiento */
    rgba(0,0,0,0.7) 60%, /* Más fuerte */
    rgba(0,0,0,1) 100% /* TOTALMENTE negro abajo */
    ), url('/resources/img_Login1.jpeg');
    background-size: cover;
    background-position: center;
    height: 100vh;
    position: relative;
}

    .bg-fondo2::before {
        content: "";
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0,0,0,0.5); 
    }

    .bg-fondo2 > * {
        position: relative;
        z-index: 1;
    }