dist/helper-js.es.js
function getOffsetParent(el) {
  var offsetParent = el.offsetParent;

  if (!offsetParent || offsetParent === document.body && getComputedStyle(document.body).position === 'static') {
    offsetParent = document.body.parentElement;
  }

  return offsetParent;
}
function getOffsetParent(el) {
  var offsetParent = el.offsetParent;

  if (!offsetParent || offsetParent === document.body && getComputedStyle(document.body).position === 'static') {
    offsetParent = document.body.parentElement;
  }

  return offsetParent;
}
function getOffsetParent ( el ) { var offsetParent = el . offsetParent ; if ( ! offsetParent || offsetParent === document . body && getComputedStyle ( document . body ) . position === 'static' ) { offsetParent = document . body . parentElement ; } return offsetParent ; }
there is some trap in el.offsetParent, so use this func to fix
there is some trap in el . offsetParent so use this func to fix