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

.stage {
  box-sizing: border-box;
  position: relative;
  min-height: 100vh;
  margin: 0;
  padding: 40px clamp(16px, 6vw, 32px) 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: #2f6df6;
  transform: scaleX(0);
  transform-origin: left;
}
@supports (animation-timeline: scroll()) {
  .bar {
    animation: fill-bar linear both;
    animation-timeline: scroll(root);
  }
}
@supports not (animation-timeline: scroll()) {
  .bar {
    transform: scaleX(0);
  }
}

@keyframes fill-bar {
  from {
    transform: scaleX(0);
  }
  to {
    transform: scaleX(1);
  }
}
.bar.is-demo {
  animation: fill-loop 2s linear infinite;
}

@keyframes fill-loop {
  0% {
    transform: scaleX(0);
  }
  90% {
    transform: scaleX(1);
  }
  100% {
    transform: scaleX(1);
  }
}
.doc {
  max-width: 380px;
  color: #fff;
}

.doc__line {
  height: 12px;
  margin: 0 0 14px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.12);
}
.doc__line.short {
  width: 60%;
}

@media (prefers-reduced-motion: reduce) {
  .bar, .bar.is-demo {
    animation: none !important;
    transform: scaleX(1);
  }
}