animation-delay

animation-delay: 250ms;

animation-delay: 2s;

animation-delay: -2s;

<section class="flex-column" id="default-example">
  <div>Animation <span id="playstatus"></span></div>
  <div id="example-element">Select a delay to start!</div>
</section>

#example-element {
  background-color: #1766aa;
  color: white;
  margin: auto;
  margin-left: 0;
  border: 5px solid #333;
  width: 150px;
  height: 150px;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
}

#playstatus {
  font-weight: bold;
}

.animating {
  animation-name: slide;
  animation-duration: 3s;
  animation-timing-function: ease-in;
  animation-iteration-count: 2;
  animation-direction: alternate;
}

@keyframes slide {
  from {
    background-color: orange;
    color: black;
    margin-left: 0;
  }
  to {
    background-color: orange;
    color: black;
    margin-left: 80%;
  }
}

"use strict";

window.addEventListener("load", () => {
  const el = document.getElementById("example-element");
  const status = document.getElementById("playstatus");

  function update() {
    status.textContent = "delaying";
    el.className = "";
    window.requestAnimationFrame(() => {
      window.requestAnimationFrame(() => {
        el.className = "animating";
      });
    });
  }

  el.addEventListener("animationstart", () => {
    status.textContent = "playing";
  });

  el.addEventListener("animationend", () => {
    status.textContent = "finished";
  });

  const observer = new MutationObserver(() => {
    update();
  });

  observer.observe(el, {
    attributes: true,
    attributeFilter: ["style"],
  });

  update();
});

animation-delay: 3s;
animation-delay: 2s, 4ms;