* { box-sizing: border-box; margin: 0; padding: 0; }
html, body {
  height: 100%;
  width: 100%;
  overflow: hidden;
}
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans TC", sans-serif;
  background: #0f172a;
  color: #f8fafc;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 24px;
  padding-top: max(24px, env(safe-area-inset-top));
  padding-bottom: max(24px, env(safe-area-inset-bottom));
}
h1 { font-size: 1.75rem; font-weight: 600; letter-spacing: 0.05em; }
#location-name { font-size: 1.25rem; color: #94a3b8; }
#qr-wrap {
  background: #fff;
  padding: 20px;
  border-radius: 16px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.4);
}
#qr-wrap canvas { display: block; }
#reader-wrap {
  width: min(90vw, 420px);
  border-radius: 16px;
  overflow: hidden;
  background: #000;
  box-shadow: 0 10px 40px rgba(0,0,0,0.4);
}
#reader-wrap.hidden { display: none; }
#reader-wrap video { border-radius: 16px; }
#result-banner {
  display: none;
  text-align: center;
  padding: 20px 28px;
  border-radius: 16px;
  font-size: 1.25rem;
  font-weight: 700;
  max-width: 90vw;
}
#result-banner.ok { display: block; background: #166534; color: #dcfce7; }
#result-banner.err { display: block; background: #991b1b; color: #fee2e2; }
#result-detail {
  display: none;
  text-align: center;
  color: #cbd5e1;
  font-size: 1rem;
}
#result-detail.show { display: block; }
#status {
  font-size: 0.95rem;
  color: #94a3b8;
  text-align: center;
  max-width: 90vw;
}
.error { color: #f87171; }
.offline { color: #fbbf24; }
#install-tip {
  display: none;
  position: fixed;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.75rem;
  color: #64748b;
  text-align: center;
  max-width: 90vw;
  line-height: 1.4;
}
@media all and (display-mode: browser) {
  #install-tip { display: block; }
}
@media all and (display-mode: standalone),
       all and (display-mode: fullscreen) {
  #install-tip { display: none !important; }
}