スクロールを付ける

<div class="scroll-indicator">
  <span>Scroll</span>
  <div class="line"></div>
</div>

.scroll-indicator {
  position: absolute;
  bottom: 10px;
  left: 50%;
  transform: translateX(-50%);
  text-align: center;
  font-family: 'Helvetica Neue', sans-serif;
  font-size: 11px;
  letter-spacing: 2px;
  color: white;
  z-index: 10;
}

.scroll-indicator .line {
  position: relative;
  width: 1px;
  height: 40px;
  margin: 8px auto 0;
  background: transparent;
  overflow: hidden;
}

.scroll-indicator .line::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 0.3px;
  height: 100%;
  background: white;
  animation: scrollDownFadeOut 1.5s ease-in-out infinite;
  transform-origin: top;
}

@keyframes scrollDownFadeOut {
  0% {
    transform: scaleY(0);
    opacity: 0.8;
  }
  70% {
    transform: scaleY(1);
    opacity: 1;
  }
  100% {
    transform: scaleY(1);
    opacity: 0;
  }
}