remove-header-footer.js

function reduceElements(element, callback, accumulator) {
	if (element !== document.body && element.parentElement) {
		return reduceElements(element.parentElement, callback, callback(accumulator, element));
	}
	return accumulator;
}

function findFullWidthElement(acc, elem) {
	if (acc) {
		return acc;
	}
	if (elem.offsetWidth > window.innerWidth * .8) {
		return elem;
	}
}

function deHeader() {
	var header = document.elementFromPoint(0,0);
	if (header) {
		var fullWidthHeader = reduceElements(header, findFullWidthElement);
		if (fullWidthHeader) {
			fullWidthHeader.parentElement.removeChild(fullWidthHeader);
		}
	}
}

function deFooter() {
	var footer = document.elementFromPoint(1, window.innerHeight - 1);
	if (footer) {
		var fullWidthFooter = reduceElements(footer, findFullWidthElement);
		if (fullWidthFooter) {
			fullWidthFooter.parentElement.removeChild(fullWidthFooter);
		}
	}
}