Infinite Staircase Illusion

HTML

CSS

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  height: 100vh;
  background: #0b0b0b;
  display: grid;
  place-items: center;
  overflow: hidden;
  font-family: system-ui, sans-serif;
}
.scene {
  position: relative;
  width: 240px;
  height: 240px;
  transform: rotateX(60deg) rotateZ(45deg);
}
.step {
  position: absolute;
  width: 120px;
  height: 30px;
  background: linear-gradient(135deg, #00f5ff, #7cffcb);
  opacity: 0.85;
  animation: move 4s linear infinite;
  box-shadow: 0 10px 30px rgba(0,255,200,0.35);
}
.step:nth-child(1) { animation-delay: 0s; }
.step:nth-child(2) { animation-delay: 0.8s; }
.step:nth-child(3) { animation-delay: 1.6s; }
.step:nth-child(4) { animation-delay: 2.4s; }
.step:nth-child(5) { animation-delay: 3.2s; }
@keyframes move {
  0% {
    transform: translate(0, 0);
    opacity: 0;
  }
  10% { opacity: 1; }
  50% {
    transform: translate(60px, 60px);
    opacity: 1;
  }
  90% { opacity: 0; }
  100% {
    transform: translate(120px, 120px);
    opacity: 0;
  }
}
.label {
  position: fixed;
  bottom: 30px;
  color: #7cffcb;
  letter-spacing: 3px;
  font-size: 12px;
  opacity: 0.6;
}