header {
    position: fixed;
    top: 0px;
    left: 0px;
    width: 100%;
}

nav {
    display: flex;
    flex-direction: row;
}

@media only screen and (min-width: 900px) {
    nav{
        padding: 24px 42px 24px 42px;
    }
}

@media only screen and (max-width: 800px) {
    nav{
        padding: 0;
    }
}