html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.hline {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  display: grid;
  align-content: center;
  gap: 18px;
}

.hline__label {
  padding-left: 16px;
  color: rgba(255, 247, 230, 0.7);
  font: 700 clamp(12px, 3.6vw, 14px)/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  letter-spacing: 0.04em;
}

.hline__track {
  display: flex;
  gap: 14px;
  padding-left: 16px;
}
@supports (animation-timeline: scroll()) {
  .hline__track {
    animation: travel linear both;
    animation-timeline: scroll(root);
  }
}
@supports not (animation-timeline: scroll()) {
  .hline__track {
    transform: none;
  }
}

.hline__card {
  flex: none;
  width: 64px;
  height: 64px;
  border-radius: 16px;
  background: #fff7e6;
  color: #17141a;
  display: grid;
  place-items: center;
  font: 700 18px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

@keyframes travel {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-120px);
  }
}
.stage.is-demo .hline__track {
  animation: travel-loop 2s ease-in-out infinite;
}

@keyframes travel-loop {
  0%, 100% {
    transform: translateX(0);
  }
  50% {
    transform: translateX(-120px);
  }
}
@media (prefers-reduced-motion: reduce) {
  .hline__track, .stage.is-demo .hline__track {
    animation: none !important;
    transform: none;
  }
}