.parallax {
        position: relative;
        background-attachment: fixed;
        background-position: center;
        background-repeat: no-repeat;
        background-size: cover;
    }

    .mi_titulo, .mis_cajas {
        opacity: 0;
        transform: translateY(250px);
        transition: opacity 0.10s ease-out, transform 0.10s ease-out;
    }

    .mi_titulo.visible, .mis_cajas.visible {
        opacity: 1;
        transform: translateY(0);
    }