Transparent header until scroll down

Development
2

I managed to get this working well enough.

js:

<script>

var dHeaderWhite = document.createElement('style');
dHeaderWhite.innerHTML = `
/*.docked. .d-header {
    position:fixed;
}*/
.d-header {
    background-color: white;
    box-shadow: 0 1px 8px rgba(0,0,0,0.18);
    -webkit-animation: fadein 0.5s;
    animation: fadein 0.5s;
}`;

var dHeaderTransparent = document.createElement('style');
dHeaderTransparent.innerHTML = `
/*.docked .d-header {
    position:absolute;
}*/
.d-header {
    background-color:transparent;
    box-shadow: unset;
    -webkit-animation: fadeout 0.5s;
    animation: fadeout 0.5s;
}`;

// When the user scrolls down the document, change from transparent background to white
$(document).ready(function($){
    $(function(){
        $(window).scroll(function(){
            
            if ($(".extra-info-wrapper")[0]) {
                // White if class exists
                document.head.appendChild(dHeaderWhite);
            } else if ($(this).scrollTop() > 150) { 
                // class doesn't exist but user has scrolled
                document.head.appendChild(dHeaderWhite);
            } else {
                // Transparent if class doesn't exist
                document.head.appendChild(dHeaderTransparent);
            }
        });
    });
});
</script>

css:

.d-header {
    background-color: transparent;
    box-shadow:unset;
}
.d-header-icons .d-icon {
    color: #9c9c9c;
}

I want the header to start off as scrollable and switched to fixed on scroll, but this doesn’t work yet. I’ll keep hacking away.