Function handler

src/js/content-script.js:9–12

()

async function doAnimation(element, property, value) {
  return new Promise((resolve) => {
    const handler = () => {
      resolve();
      element.removeEventListener("transitionend", handler);
    };
    element.addEventListener("transitionend", handler);
    window.requestAnimationFrame(() => {
      element.style[property] = value;