positionRulePopup function

function positionRulePopup(anchor: HTMLElement): void {
  if (!rulePopupElement) return;

  const rect = anchor.getBoundingClientRect();
  const popupWidth = 280;
  const popupHeight = 280;

  let top = rect.bottom + window.scrollY + 4;
  let left = rect.left + window.scrollX;

  if (left + popupWidth > window.innerWidth + window.scrollX - 8) {
    left = window.innerWidth + window.scrollX - popupWidth - 8;
  }
  left = Math.max(window.scrollX + 8, left);

  if (top + popupHeight > window.innerHeight + window.scrollY) {
    top = rect.top + window.scrollY - popupHeight - 4;
  }

  rulePopupElement.style.top = `${top}px`;
  rulePopupElement.style.left = `${left}px`;
}