Flip In

<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/bundles/anime.umd.min.js"></script>
<script>
  (function () {
    // Flip In: the element flips into view round its horizontal or vertical
    // axis, starting edge-on and swinging past flat a couple of times before
    // it settles.
    // Usage: <div data-flip-in>…</div>
    // Optional: data-axis ("x", default, tips over the horizontal axis; "y"
    // turns round the vertical one; give both, "x y", and each loop uses the
    // next), data-perspective (px, smaller is more dramatic, default 800),
    // data-duration (ms, default 1000), data-delay (ms before the first
    // entrance), data-loop (hold, fade away and flip in again), data-hold (ms
    // to stay when looping, default 1400).
    var DEFAULTS = { axis: 'x', perspective: 800, duration: 1000, delay: 0, hold: 1400 };

    function reduced() {
      return window.matchMedia('(prefers-reduced-motion: reduce)').matches;
    }

    function enter(el, axis, done) {
      var d = el.dataset;
      var t = +d.duration || DEFAULTS.duration;
      var prop = axis === 'y' ? 'rotateY' : 'rotateX';
      var other = axis === 'y' ? 'rotateX' : 'rotateY';
      var start = { opacity: 0, perspective: (+d.perspective || DEFAULTS.perspective) + 'px' };
      start[prop] = 90;
      start[other] = 0;
      anime.utils.set(el, start);
      var props = {
        opacity: { to: 1, duration: t * 0.6, ease: 'linear' },
        onComplete: done
      };
      // Edge-on, then past flat, back, and a smaller swing to rest.
      props[prop] = [
        { to: -20, duration: t * 0.4, ease: 'in(2)' },
        { to: 10, duration: t * 0.2, ease: 'inOut(2)' },
        { to: -5, duration: t * 0.2, ease: 'inOut(2)' },
        { to: 0, duration: t * 0.2, ease: 'out(2)' }
      ];
      anime.animate(el, props);
    }

    function cycle(el) {
      var d = el.dataset;
      var s = el._fli;
      var axes = (d.axis || DEFAULTS.axis).split(/[\s,]+/);
      enter(el, axes[s.n++ % axes.length], function () {
        if (d.loop === undefined || d.loop === 'false') return;
        setTimeout(function () {
          anime.animate(el, {
            opacity: 0,
            duration: 400,
            ease: 'out(2)',
            onComplete: function () {
              // Wait until it's back on screen before the next entrance.
              setTimeout(function () {
                if (s.visible) cycle(el);
                else s.waiting = true;
              }, 500);
            }
          });
        }, +d.hold || DEFAULTS.hold);
      });
    }

    function init() {
      var io = new IntersectionObserver(function (entries) {
        entries.forEach(function (e) {
          var s = e.target._fli;
          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-flip-in]').forEach(function (el) {
        if (el._fli) return;
        el._fli = { n: 0 };
        if (reduced()) return;
        anime.utils.set(el, { opacity: 0 });
        io.observe(el);
      });
    }

    if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', init);
    else init();
  })();
</script>

<div class="card" data-flip-in>Card added</div>

<!-- or turning round the vertical axis: -->
<div class="card" data-flip-in data-axis="y">Card added</div>