<div class="box">Hello World</div>
@keyframes slide-in {
  from {
    transform: translateX(-100%);
    opacity: 0.25;
  }
  to {
    transform: translateX(0%);
    opacity: 1;
  }
}

.box {
  animation: slide-in 1000ms;
  animation-delay: 500ms;
  animation-fill-mode: backwards;
}

.box {
  width: 100px;
  height: 100px;
  background: slateblue;
  padding: 8px;
  display: grid;
  place-content: center;
  color: white;
  text-align: center;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.