/* FONDO DE IMAGEN */
.sections_group {
    background-image: url(https://www.spainultracup.com/wp-content/uploads/2016/03/fondo-eventos-arista-eventos.jpg);
    background-size: 100%;

    background-attachment: fixed;
    background-position:center;
    background-repeat: no-repeat;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    min-height: 500px;
}