Select child element from parent – Plain Javascript

I need some help with Javascript.
What I try to do is move an element to another element.

Normaly I can use the queryselector but in this case I can not because there are multiple elements with the class "destination". To get the result what I want I need select first the parent element "catalog-item" and after that the child "destination".

I need some help to get the right element catalog-item->destination

<div id="catalog-item">
    <div class="destination">
    </div>
</div>

<div id="move"></div>

<script type="text/javascript>
var itm = document.getElementById("move");
var cln = itm.cloneNode(true);
itm.remove();
document.getElementById("catalog-item").children(".destination").appendChild(cln);
</script>

Who can help me?

>Solution :

You can select the child element with querySelector by writing document.querySelector("#catalog-item .destination"). Just put a space between them.