load.html

<link rel="stylesheet" href="/scss.scss">
<div class="cover">
    <div class="dna">
        <div class=" contain ">
            <div class="spike spike1 "></div>
            <div class="spike spike2 "></div>
            <div class="spike spike3 "></div>
            <div class="spike spike4 "></div>
            <div class="spike spike5 "></div>
            <div class="spike spike6 "></div>
            <div class="spike spike7 "></div>
            <div class="spike spike8 "></div>
            <div class="spike spike9 "></div>
            <div class="spike spike10 "></div>
            <div class="spike spike11 "></div>
            <div class="spike spike12 "></div>
            <div class="spike spike13 "></div>
            <div class="spike spike14 "></div>
            <div class="spike spike15 "></div>
        </div>
    </div>
</div>
<script>
    window.addEventListener("load", function() {
        const loader = document.querySelector(".cover");
        loader.className += " hidden";
    });
</script>