body {
    background-image: url(background-header.jpg);
    background-position: top;
    background-attachment:fixed;
    background-size: cover;
    color: #fff;
    text-align: center;
    
    div.text {
        display: flex;
        flex-direction: column;
        margin: 20em auto 0;
        justify-content: center;
    }
}