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);
}

.fs {
  display: flex;
  flex-direction: column;
  gap: 8px;
  box-sizing: border-box;
  width: min(100%, 420px);
}

.fs__tabs {
  display: flex;
  gap: 8px;
}

.fs__tab {
  flex: 1 1 0;
  appearance: none;
  cursor: pointer;
  padding: 4px 8px;
  border: 1px solid rgba(255, 247, 230, 0.18);
  border-radius: 999px;
  background: transparent;
  color: #fff7e6;
  font-family: system-ui, -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 700;
  font-size: 12px;
  line-height: 1.4;
  transition: background-color 220ms cubic-bezier(0.2, 0.8, 0.2, 1), color 220ms cubic-bezier(0.2, 0.8, 0.2, 1), border-color 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.fs__tab[aria-pressed=true] {
  border-color: #fff7e6;
  background: #fff7e6;
  color: #17141a;
}

.fs__tab:focus-visible {
  outline: 2px solid #5b8cf8;
  outline-offset: 2px;
}

.fs__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.fs__pane {
  display: flex;
  flex-direction: column;
  gap: 4px;
  box-sizing: border-box;
  padding: 8px;
  border: 1px solid rgba(255, 247, 230, 0.18);
  border-radius: 12px;
  background: rgba(255, 247, 230, 0.02);
}

.fs__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.fs__chip {
  font-family: ui-monospace, "Cascadia Mono", Consolas, "Liberation Mono", monospace;
  font-weight: 700;
  font-size: 10px;
  line-height: 1.4;
  letter-spacing: 0.08em;
  color: #beb7ad;
}

.fs__mark {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #5b8cf8;
  opacity: 0;
}

.fs__spec {
  margin: 0;
  color: #fff7e6;
  font-size: clamp(13px, 4.6vw, 20px);
  font-weight: 600;
  line-height: 1.45;
}

.fs__spec--serif {
  font-family: ui-serif, Georgia, "Times New Roman", "Noto Serif KR", serif;
}

.fs__spec--sans {
  font-family: system-ui, -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.fs__spec--mono {
  font-family: ui-monospace, "Cascadia Mono", Consolas, "Liberation Mono", monospace;
}

.fs__stack {
  margin: 0;
  color: #beb7ad;
  font-family: ui-monospace, "Cascadia Mono", Consolas, "Liberation Mono", monospace;
  font-weight: 500;
  font-size: 9px;
  line-height: 1.4;
}

.fs__note {
  margin: 0;
  color: #beb7ad;
  font-family: system-ui, -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 500;
  font-size: 11px;
  line-height: 1.4;
}

.fs.is-demo .fs__pane {
  animation-name: fsGlow;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}

.fs.is-demo .fs__pane:nth-child(2) {
  animation-delay: 0.6666666667s;
}

.fs.is-demo .fs__pane:nth-child(3) {
  animation-delay: 1.3333333333s;
}

.fs.is-demo .fs__spec {
  animation-name: fsRise;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}

.fs.is-demo .fs__pane:nth-child(2) .fs__spec {
  animation-delay: 0.6666666667s;
}

.fs.is-demo .fs__pane:nth-child(3) .fs__spec {
  animation-delay: 1.3333333333s;
}

.fs.is-demo .fs__mark {
  animation-name: fsDot;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}

.fs.is-demo .fs__pane:nth-child(2) .fs__mark {
  animation-delay: 0.6666666667s;
}

.fs.is-demo .fs__pane:nth-child(3) .fs__mark {
  animation-delay: 1.3333333333s;
}

@keyframes fsGlow {
  0% {
    background: rgba(255, 247, 230, 0.1);
    border-color: rgba(255, 247, 230, 0.6);
  }
  33%, 100% {
    background: rgba(255, 247, 230, 0.02);
    border-color: rgba(255, 247, 230, 0.18);
  }
}
@keyframes fsRise {
  0% {
    transform: translateY(5px);
  }
  33% {
    transform: translateY(-1px);
  }
  39%, 100% {
    transform: translateY(5px);
  }
}
@keyframes fsDot {
  0% {
    opacity: 1;
    transform: scale(1);
  }
  33%, 100% {
    opacity: 0;
    transform: scale(0.4);
  }
}
@media (max-width: 340px) {
  .fs {
    gap: 4px;
  }
  .fs__tabs {
    gap: 4px;
  }
  .fs__tab {
    padding: 4px;
    font-size: 11px;
  }
  .fs__pane {
    gap: 0;
  }
  .fs__spec {
    font-size: 13px;
    line-height: 1.4;
  }
  .fs__stack {
    font-size: 9px;
  }
  .fs__note {
    font-size: 10px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .fs.is-demo .fs__pane,
  .fs.is-demo .fs__spec,
  .fs.is-demo .fs__mark {
    animation: none !important;
    transform: none !important;
    opacity: 0 !important;
    background: rgba(255, 247, 230, 0.02) !important;
    border-color: rgba(255, 247, 230, 0.18) !important;
  }
}