https://www.vetofish.com/scripts/word-reveal.js

1(() => {
2  const initialise = () => {
3    const titles = document.querySelectorAll("[data-word-reveal-ready]:not([data-word-reveal-observed])");
4    titles.forEach((title) => { title.dataset.wordRevealObserved = "true"; });
5    if (window.matchMedia("(prefers-reduced-motion: reduce)").matches || !("IntersectionObserver" in window)) {
6      titles.forEach((title) => title.classList.add("is-visible"));
7      return;
8    }
9    const observer = new IntersectionObserver((entries) => {
10      entries.forEach((entry) => {
11        if (!entry.isIntersecting) return;
12        entry.target.classList.add("is-visible");
13        observer.unobserve(entry.target);
14      });
15    }, { threshold: 0.35 });
16    titles.forEach((title) => observer.observe(title));
17  };
18  document.readyState === "loading" ? document.addEventListener("DOMContentLoaded", initialise) : initialise();
19})();