* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: #f5f5f7;
  color: #1d1d1f;
  min-height: 100vh;
}

.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 40px 20px;
}

header {
  text-align: center;
  margin-bottom: 32px;
}

header h1 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 16px;
}

.track-switcher {
  display: inline-flex;
  background: #e5e5ea;
  border-radius: 8px;
  padding: 2px;
}

.track-btn {
  padding: 8px 20px;
  border: none;
  background: transparent;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  color: #666;
  transition: all 0.2s;
}

.track-btn.active {
  background: white;
  color: #1d1d1f;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.loading, .error {
  text-align: center;
  padding: 40px;
  color: #666;
  font-size: 15px;
}

.error { color: #ff3b30; }

.build-info {
  text-align: center;
  margin-bottom: 24px;
}

.version {
  font-size: 18px;
  font-weight: 600;
  display: block;
  margin-bottom: 4px;
}

.updated {
  font-size: 13px;
  color: #86868b;
}

.platforms {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 480px) {
  .platforms { grid-template-columns: 1fr; }
}

.card {
  background: white;
  border-radius: 16px;
  padding: 24px;
  text-align: center;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

.card[hidden] { display: none; }

.card-icon {
  color: #86868b;
  margin-bottom: 12px;
}

.card h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 4px;
}

.card-detail {
  font-size: 13px;
  color: #86868b;
  margin-bottom: 16px;
}

.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: opacity 0.2s;
}

.btn:hover { opacity: 0.85; }

.btn-primary {
  background: #007AFF;
  color: white;
}

.btn-disabled {
  background: #e5e5ea;
  color: #86868b;
  pointer-events: none;
}

.card-note {
  font-size: 11px;
  color: #aeaeb2;
  margin-top: 10px;
}

footer {
  text-align: center;
  margin-top: 40px;
  font-size: 12px;
  color: #aeaeb2;
}