Gradual reduction of the string. Smooth line reduction. Smooth narrowing of the string.

js.js

export function easeInOutQuad(t) {
  return t * (2 - t);
}

/**
 * Erase symbol one by one
 * @param {Element} element
 */
export function smoothErase(element) {
  const text = element.innerHTML;
  const time = () => easeInOutQuad(element.innerHTML.length / text.length) * 60;
  const frame = () => {
    if (element.innerHTML.length > 0) {
      const cur = element.innerHTML;
      element.innerHTML = cur.slice(0, cur.length - 1);
      setTimeout(frame, time());
    }
  };

  setTimeout(frame, time());
}