html,body{margin:0;height:100%;background:#000;overflow:hidden;font-family:Arial,sans-serif}
.wrap{display:flex;justify-content:center;align-items:center;height:100%;perspective:900px}
.cube{color:#fff;font-size:4rem;font-weight:700;text-align:center;transform-style:preserve-3d;animation:spin 8s linear infinite;text-shadow:0 0 18px #fff}
.cube span{font-size:5rem;display:block}
@keyframes spin{from{transform:rotateY(0)}to{transform:rotateY(360deg)}}