#inert — 10LOC

Chrome APIsintermediate

The inert attribute to trap focus outside a modal

export const openModal = (modalRoot: HTMLElement) => {
  const siblings = Array.from(document.body.children).filter(
    (el): el is HTMLElement => el !== modalRoot && el instanceof HTMLElement,
  );
  siblings.forEach((el) => {

Setting .inert on everything outside a custom modal removes it from tab order, clicks, and the a11y tree in one line — no focus-trap library.