Text Scramble.

const CHARS = "!<>-_\\/[]{}=+*^?#";

function scramble(el, text, duration = 700) {
  const start = performance.now();
  (function tick(now) {
    const p = Math.min((now - start) / duration, 1);
    const solid = Math.floor(p * text.length);
    el.textContent = text
      .split("")
      .map((c, i) => (i < solid ? c : CHARS[Math.floor(Math.random() * CHARS.length)]))
      .join("");
    if (p < 1) requestAnimationFrame(tick);
  })(start);
}