<h1>Easily timed changes with random durations.</h1> 
<section>
  <div class="emoji">😊</div>
<div class="emoji">😊</div>
<div class="emoji">😊</div>
<div class="emoji">😊</div>
<div class="emoji">😊</div>

</section>
@import url('https://fonts.googleapis.com/css2?family=Nunito&family=Signika+Negative:wght@400;600&display=swap');

body {
  background-color: #fff;
  color: black;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  font-family: "Signika Negative", sans-serif, Arial;
  margin: 1rem;
  min-height: 100vh;
  overflow: hidden;
  z-index: -1;
}

h1 {
  font-weight: 400;
  font-size: 1.8rem;
}

section {
  position: relative;
  flex: 0 0 auto;
  width: 600px;
  border: solid 3px white;
  padding: 1rem;
}

section:after {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  width: 2px;
  background-color: #313639;
  height: 100%;
  z-index: -1;
}

section:after {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  height: 100%;
  border-left: 3px solid white;
}

.emoji {
  margin: 6px 0;
  width: 40px;
  height: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 40px;
  will-change: transform;
  z-index: 2;
}

gsap.registerPlugin(TextPlugin);

gsap.utils.toArray(".emoji").forEach(element => {
  
  gsap.timeline({ repeat: -1, yoyo: true })
    .to(element, {
      x: 500,
      xPercent: 100,
      transformOrigin: 'center',
      ease: "none",
      duration: "random(2, 5)"
    })
    .set(element, {
      text: "🥳",
    }, "<50%");
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://unpkg.co/gsap@3/dist/gsap.min.js
  2. https://unpkg.com/gsap@3/dist/TextPlugin.min.js