html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
}


nav {
    position: sticky;
    top: 0;
    width: 100%;
    background-color: white;
    z-index: 50; /* optional, damit es über anderen Elementen liegt */
}



#mobile-menu {
    padding-bottom: 1rem;
}

#section1 {
    max-width: 110rem;
    margin-left: auto;
    margin-right: auto;
    padding-left: 1rem;
    padding-right: 1rem;
    text-align: center;
}