Flash

<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/bundles/anime.umd.min.js"></script>
<script>
  (function () {
    // Flash: the element blinks off and on, twice by default, like a light
    // catching your eye. Quick fades rather than a hard cut, so it stays easy
    // on the eyes.
    // Usage: <span data-flash>…</span>
    // Optional: data-times (how many blinks, default 2), data-min (opacity at
    // the bottom of a blink, 0 to 1, default 0), data-duration (ms for all the
    // blinks, default 900), data-delay (ms before the first flash), data-loop
    // (flash again every so often while in view), data-every (ms of rest
    // between loops, default 1800), data-hover (also flash on hover or tap).
    // Script use: animacious.flash(el) flashes it from code.
    var DEFAULTS = { times: 2, min: 0, duration: 900, delay: 0, every: 1800 };

    function on(v) { return v !== undefined && v !== 'false'; }
    function reduced() { return window.matchMedia('(prefers-reduced-motion: reduce)').matches; }

    function play(el, done) {
      var s = el._fls;
      if (s.busy) { if (done) s.after = done; return; }
      if (reduced()) { if (done) done(); return; }
      s.busy = true;
      var d = el.dataset;
      function finish() {
        s.busy = false;
        var after = s.after;
        s.after = null;
        if (done) done();
        if (after) after();
      }
      var times = Math.max(1, Math.round(+d.times || DEFAULTS.times));
      var min = d.min === undefined ? DEFAULTS.min : Math.min(1, Math.max(0, +d.min));
      var frames = { '0%': { opacity: 1 } };
      for (var i = 0; i < times; i++) {
        // Each blink: fade down fast, hold a moment, come back up.
        var start = (i / times) * 100, span = 100 / times;
        frames[(start + span * 0.3).toFixed(2) + '%'] = { opacity: min, ease: 'in(2)' };
        frames[(start + span * 0.5).toFixed(2) + '%'] = { opacity: min, ease: 'linear' };
        frames[(start + span * 0.8).toFixed(2) + '%'] = { opacity: 1, ease: 'out(2)' };
      }
      frames['100%'] = { opacity: 1 };
      anime.animate(el, {
        keyframes: frames,
        duration: +d.duration || DEFAULTS.duration,
        onComplete: finish
      });
    }

    function cycle(el) {
      var s = el._fls;
      play(el, function () {
        if (!on(el.dataset.loop)) return;
        clearTimeout(s.timer);
        s.timer = setTimeout(function () {
          if (s.visible) cycle(el);
          else s.waiting = true;
        }, +el.dataset.every || DEFAULTS.every);
      });
    }

    function init() {
      var io = new IntersectionObserver(function (entries) {
        entries.forEach(function (e) {
          var s = e.target._fls;
          s.visible = e.isIntersecting;
          if (!e.isIntersecting) return;
          if (!s.started) {
            s.started = true;
            setTimeout(function () { cycle(e.target); }, +e.target.dataset.delay || DEFAULTS.delay);
          } else if (s.waiting) {
            s.waiting = false;
            cycle(e.target);
          }
        });
      }, { threshold: 0.2 });
      document.querySelectorAll('[data-flash]').forEach(function (el) {
        if (el._fls) return;
        el._fls = {};
        if (on(el.dataset.hover)) {
          el.addEventListener('pointerenter', function () { play(el); });
          el.addEventListener('pointerdown', function () { play(el); });
        }
        if (!reduced()) io.observe(el);
      });
    }

    window.animacious = window.animacious || {};
    window.animacious.flash = function (el) { if (el._fls) play(el); };
    if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', init);
    else init();
  })();
</script>

<span class="badge" data-flash>Live</span>

<!-- or three softer blinks, repeating: -->
<span class="badge" data-flash data-times="3" data-min="0.2" data-loop>Live</span>