:root {
  --color-paper: #f4f1e8;
  --color-paper-deep: #ece7d9;
  --color-ink: #1c1b18;
  --color-ink-soft: #6b665b;
  --color-line: #d9d3c3;
  --color-accent: #d8442a;
  --color-accent-deep: #b0331d;
  --color-mark: #e0a92e;
  --font-display: Inter, Noto Sans TC, sans-serif;
  --font-body: Inter, Noto Sans TC, sans-serif;
  --font-mono: Inter, Noto Sans TC, sans-serif;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

.tool-intro {
  margin-block: 16px 40px;
  font-size: 1rem;
  line-height: 1.7;
  color: #1c1b18;
}

.os-selector {
  display: flex;
  gap: 16px;
  margin-block: 24px 40px;
}

.os-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 24px 40px;
  border: 1.5px solid #d9d3c3;
  background: transparent;
  cursor: pointer;
  border-radius: 2px;
  transition: border-color 0.4s cubic-bezier(0.22, 0.61, 0.36, 1), background 0.4s cubic-bezier(0.22, 0.61, 0.36, 1);
  min-width: 180px;
  text-align: center;
}
.os-card:hover {
  border-color: #1c1b18;
}
.os-card.is-selected {
  border-color: #d8442a;
  background: color-mix(in srgb, #d8442a 7%, transparent);
}

.os-card-icon {
  width: 44px;
  height: 44px;
  color: #1c1b18;
  margin-bottom: 4px;
}

.os-card-icon-win {
  color: unset;
}

.os-card-name {
  font-size: 1rem;
  font-weight: 700;
  color: #1c1b18;
  letter-spacing: 0.04em;
}

.os-card-desc {
  font-size: 1rem;
  color: #6b665b;
}

.launch-area {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
}

.launch-btn {
  padding: 12px 36px;
  font-size: 1rem;
  letter-spacing: 0.04em;
}

.launch-hint {
  font-size: 1rem;
  color: #6b665b;
}
.launch-hint kbd {
  font-family: monospace;
  font-size: 0.85em;
  padding: 2px 7px;
  border: 1px solid #d9d3c3;
  border-radius: 3px;
  background: #ece7d9;
  color: #1c1b18;
}

.fuo-overlay {
  position: fixed;
  inset: 0;
  z-index: 99999;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  user-select: none;
  cursor: default;
}
.fuo-overlay.mac-mode {
  background: #000;
}
.fuo-overlay.mac-mode .fuo-win {
  display: none;
}
.fuo-overlay.mac-mode .fuo-mac {
  display: flex;
}
.fuo-overlay.win-mode {
  background: #0b1120;
}
.fuo-overlay.win-mode .fuo-mac {
  display: none;
}
.fuo-overlay.win-mode .fuo-win {
  display: flex;
}

.fuo-esc-hint {
  position: absolute;
  top: 20px;
  right: 24px;
  font-family: monospace;
  font-size: 11px;
  color: rgba(255, 255, 255, 0.25);
  letter-spacing: 0.12em;
  pointer-events: none;
  transition: opacity 1.2s ease;
}
.fuo-esc-hint.is-hidden {
  opacity: 0;
}

.fuo-mac {
  flex-direction: column;
  align-items: center;
  width: 100%;
  height: 100%;
  justify-content: center;
  padding-bottom: 8vh;
  position: relative;
}

.fuo-apple-logo {
  width: 70px;
  height: 70px;
  color: #fff;
  margin-bottom: 22px;
}

.fuo-mac-os-name {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 27px;
  font-weight: 300;
  color: #fff;
  letter-spacing: -0.015em;
  margin-bottom: 6px;
}

.fuo-mac-status {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 13px;
  color: #8e8e93;
  margin-bottom: 22px;
}

.fuo-mac-bar-track {
  width: 310px;
  height: 4px;
  background: rgba(255, 255, 255, 0.14);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 11px;
}

.fuo-mac-bar-fill {
  height: 100%;
  background: #fff;
  border-radius: 2px;
  width: 0%;
  transition: width 1.2s linear;
}

.fuo-mac-time {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 12px;
  color: #636366;
  min-height: 16px;
}

.fuo-mac-footer {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.fuo-mac-note {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 12px;
  color: #636366;
  white-space: nowrap;
}

.fuo-mac-copyright {
  font-family: -apple-system, "Helvetica Neue", Arial, sans-serif;
  font-size: 10px;
  color: rgba(255, 255, 255, 0.12);
  white-space: nowrap;
}

.fuo-win {
  flex-direction: column;
  align-items: center;
  width: 100%;
  height: 100%;
  justify-content: center;
  padding-bottom: 8vh;
  position: relative;
}

.fuo-win-logo {
  width: 68px;
  height: 68px;
  margin-bottom: 44px;
  flex-shrink: 0;
}

.fuo-win-percent {
  font-family: "Segoe UI", "Microsoft JhengHei", Arial, sans-serif;
  font-size: 108px;
  font-weight: 100;
  color: #fff;
  line-height: 1;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  font-variant-numeric: tabular-nums;
}

.fuo-win-title {
  font-family: "Segoe UI", "Microsoft JhengHei", Arial, sans-serif;
  font-size: 20px;
  font-weight: 300;
  color: #fff;
  margin-bottom: 6px;
}

.fuo-win-sub {
  font-family: "Segoe UI", "Microsoft JhengHei", Arial, sans-serif;
  font-size: 14px;
  font-weight: 300;
  color: rgba(255, 255, 255, 0.55);
  margin-bottom: 36px;
}

.fuo-win-dots {
  display: flex;
  gap: 10px;
}

.fuo-win-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.7);
  animation: fuoWinDot 1.4s ease-in-out infinite;
}
.fuo-win-dot:nth-child(1) {
  animation-delay: 0s;
}
.fuo-win-dot:nth-child(2) {
  animation-delay: 0.18s;
}
.fuo-win-dot:nth-child(3) {
  animation-delay: 0.36s;
}
.fuo-win-dot:nth-child(4) {
  animation-delay: 0.54s;
}
.fuo-win-dot:nth-child(5) {
  animation-delay: 0.72s;
}

@keyframes fuoWinDot {
  0%, 80%, 100% {
    opacity: 0.18;
    transform: scale(0.75);
  }
  40% {
    opacity: 1;
    transform: scale(1);
  }
}
.fuo-win-footer {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  text-align: center;
}

.fuo-win-note {
  font-family: "Segoe UI", "Microsoft JhengHei", Arial, sans-serif;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.4);
  white-space: nowrap;
}