.achtergrondfoto {
    background-image: url("../images/Froukje/froukje-davidvandartel-compressed-5.jpg");
    background-repeat: no-repeat;
    background-position: 50% 20%;

    background-size: cover;
    width: 100%;
    height: 100vh;
    min-height: 40em;/
    max-height: 20em;
    background-attachment:fixed;/
}