html,body{
    margin: 0;
    padding: 0;
}

.main{
    display: flex;
    width: 100%;
    height: 100vh;
    align-items: center;
    justify-content: center;
    background: url("../img/sfondo-sito.jpg") center center no-repeat;
    background-size: cover;
}

.logo{
    width: 90%;
    max-width: 700px;
}

.logo img{
    max-width: 100%;
}