Replacing jQuery .outerHeight() with Javascript Pin

I am working on replacing this jQuery code written in Typescript into Vanilla JavaScript for edit .pdf purposes. I have problem resizing the window. Replacing .outerHeight() with offsetHeight doesn't work

 

windowResizeHandler: () => void = () => {
		let body = document.querySelector("body");
		let height = parseInt(window.getComputedStyle(body).height);
		//suppose there is a #header element which takes some area.

		let headHeight = $("#header").outerHeight();
		let rightHeight = height;
		if ($("#header").is(":visible")) {
			rightHeight = height - headHeight;
		}
		$("#right").height(rightHeight);
		WebPDF.updateLayer();

HTML

 

<page-container>
		<div id="docViewer" ref="docViewer" style="background: #dddedf;"></div>
	</page-container>