* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background-image: url('../images/extract_data.jpg');
  background-size: cover;
  overflow: hidden;
}

ul {
  overflow: hidden;
  perspective: 900px;
  list-style: none;
  height: 100vh;
  max-height: 800px;
  min-height: 400px;
  text-align: center;
}

@keyframes width-sway {
  0%, 100% {
    width: 500px;
  }
  50% {
    width: 100%;
  }
}
li {
  position: absolute;
  top: 0;
  margin: auto;
  width: 100%;
  transform: translateY(100vh);
  font-size: 6rem;
  font-family: sans-serif;
  font-weight: bold;
  color: #ffffdd;
  animation: 5.3333333333s spiral-staircase linear infinite;
  white-space: nowrap;
}

li:nth-child(1) {
  animation-delay: 0.3333333333s;
}

li:nth-child(2) {
  animation-delay: 0.6666666667s;
}

li:nth-child(3) {
  animation-delay: 1s;
}

li:nth-child(4) {
  animation-delay: 1.3333333333s;
}

li:nth-child(5) {
  animation-delay: 1.6666666667s;
}

li:nth-child(6) {
  animation-delay: 2s;
}

li:nth-child(7) {
  animation-delay: 2.3333333333s;
}

li:nth-child(8) {
  animation-delay: 2.6666666667s;
}

li:nth-child(9) {
  animation-delay: 3s;
}

li:nth-child(10) {
  animation-delay: 3.3333333333s;
}

li:nth-child(11) {
  animation-delay: 3.6666666667s;
}

li:nth-child(12) {
  animation-delay: 4s;
}

li:nth-child(13) {
  animation-delay: 4.3333333333s;
}

li:nth-child(14) {
  animation-delay: 4.6666666667s;
}

li:nth-child(15) {
  animation-delay: 5s;
}

li:nth-child(16) {
  animation-delay: 5.3333333333s;
}

@keyframes spiral-staircase {
  0% {
    transform: rotateY(90deg) translateY(105vh) rotate(0deg) scale(0);
    opacity: 0;
  }
  40% {
    transform: rotateY(90deg) translateY(61vh) rotate(0deg) scale(0);
    opacity: 0;
  }
  50% {
    transform: rotateY(0deg) translateY(55vh) rotate(0deg) scale(0.50);
    opacity: 1;
  }
  75% {
    transform: rotateY(-60deg) translateY(27.5vh) rotate(0deg) scale(1);
    opacity: 1;
  }
  100% {
    transform: rotateY(-90deg) translateY(-5vh) rotate(0deg) scale(1.2);
    opacity: 0;
  }
}
