header {

    background-image: url('Cover.jpg');
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center
}

.headertext {
    padding-top: 10%;
    padding-bottom: 10%;
    color: white;
    font-weight: bold;

}
nav li{
    margin-left: 5%;
    margin-right: 5%;
}