.card{
    margin-top: 5rem;
}
.hero{
    background-image: url(../img/progetti/header.jpg);
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    height: 90vh;
    background-attachment: fixed;
}
.txt-hero{
    width: 65%;
}
.overlay{
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}
@media screen and (max-width: 768px){
    .hero{
        height: 50vh;
        background-attachment: scroll;

    }
    .txt-hero{
        width: 90%;
    }
    
}