Obter posição do elemento
// Without Jquery
function offset(el) {
var rect = el.getBoundingClientRect(),
scrollLeft = window.pageXOffset || document.documentElement.scrollLeft,
scrollTop = window.pageYOffset || document.documentElement.scrollTop;
return { top: rect.top + scrollTop, left: rect.left + scrollLeft }
}
// example use
var div = document.querySelector('div');
var divOffset = offset(div);
console.log(divOffset.left, divOffset.top);
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