body {
    background-color: black;
    color: white;
    text-align: center;
}

#titel {
    font-family: "Times New Roman", serif;
    font-size: 50px;
    display: inline-block;
}

#titel2 {
    font-family: "Times New Roman", serif;
    font-size: 50px;
    display: none;
}

.nav {
    display: inline-block;
    padding: 0 10% 0 10%;
}

a {
    font-family: "Times New Roman", serif;
    color: white;
    font-size: 25px;
}

@media screen and (max-width: 800px) {
    .navigation {
        width: 200px;
        margin: 0 10% 0 10%;
    }
    #titel {
        display: none;
    }
    #titel2 {
        display: block;
    }
}