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

.stage {
  min-height: 100vh;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.sentinel {
  height: 1px;
}

.head {
  position: sticky;
  top: 0;
  z-index: 2;
  height: 56px;
  display: flex;
  align-items: center;
  padding: 0 clamp(16px, 5vw, 24px);
  background: #17141a;
  color: #fff7e6;
  font-weight: 800;
  font-size: 18px;
  line-height: 1;
  font-family: inherit;
  letter-spacing: 0.04em;
}

.subnav {
  position: sticky;
  top: 56px;
  z-index: 1;
  display: flex;
  gap: 4px;
  padding: clamp(6px, 3vh, 10px) clamp(16px, 5vw, 24px);
  background: #17141a;
  border-bottom: 4px solid transparent;
  transition: border-color 220ms ease-out;
}
.subnav.is-stuck {
  border-bottom-color: #fff7e6;
}
.subnav__tab {
  padding: 6px 14px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 13px;
  line-height: 1;
  font-family: inherit;
  color: rgba(255, 255, 255, 0.6);
}
.subnav__tab.is-active {
  color: #17141a;
  background: #fff7e6;
}

.subnav.is-demo {
  animation: stuck-loop 2s ease-out infinite;
}

@keyframes stuck-loop {
  0%, 5% {
    border-bottom-color: transparent;
  }
  40%, 60% {
    border-bottom-color: #fff7e6;
  }
  95%, 100% {
    border-bottom-color: transparent;
  }
}
.page {
  padding: clamp(8px, 4vh, 20px) 24px 0;
}

.page__line {
  height: 10px;
  margin: 0 0 clamp(6px, 3vh, 14px);
  border-radius: 4px;
  background: rgba(23, 20, 26, 0.14);
}
.page__line.short {
  width: 60%;
}

@media (prefers-reduced-motion: reduce) {
  .subnav {
    transition: none;
  }
  .subnav.is-demo {
    animation: none !important;
    border-bottom-color: #fff7e6;
  }
}