:root {
  --bg: #0f1020;
  --card: #1a1c33;
  --card-2: #23264a;
  --text: #e8eaff;
  --muted: #9aa0c7;
  --accent: #8b5cf6;
  --accent-2: #6366f1;
  --ok: #22c55e;
  --warn: #f59e0b;
  --danger: #ef4444;
  --radius: 16px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #eef0fb;
    --card: #ffffff;
    --card-2: #f1f2fb;
    --text: #1a1c33;
    --muted: #5b608a;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  background: radial-gradient(1200px 800px at 50% -10%, var(--card-2), var(--bg));
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.card {
  width: 100%;
  max-width: 460px;
  background: var(--card);
  border: 1px solid rgba(139, 92, 246, 0.25);
  border-radius: var(--radius);
  padding: 24px 22px 18px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}

.hd h1 {
  margin: 0;
  font-size: 24px;
  letter-spacing: 0.5px;
}
.hd h1 .en {
  font-size: 14px;
  color: var(--muted);
  font-weight: 500;
  margin-left: 6px;
}
.sub {
  margin: 6px 0 18px;
  color: var(--muted);
  font-size: 13px;
}

.field {
  display: block;
  margin-bottom: 14px;
}
.field span {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
}
.field input {
  width: 100%;
  padding: 12px 14px;
  font-size: 18px;
  border-radius: 12px;
  border: 1px solid rgba(139, 92, 246, 0.35);
  background: var(--card-2);
  color: var(--text);
  outline: none;
}
.field input:focus { border-color: var(--accent); }

.toggles {
  display: flex;
  gap: 18px;
  margin-bottom: 16px;
}
.switch {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
  cursor: pointer;
}
.switch input { width: 16px; height: 16px; accent-color: var(--accent); }

.btns { display: flex; gap: 10px; }
button {
  flex: 1;
  padding: 12px 14px;
  font-size: 15px;
  border-radius: 12px;
  border: 1px solid transparent;
  cursor: pointer;
  font-weight: 600;
  transition: transform 0.05s ease, filter 0.2s ease;
}
button:active { transform: scale(0.98); }
.primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #fff; }
.ghost { background: var(--card-2); color: var(--text); border-color: rgba(139, 92, 246, 0.3); }

.meter {
  margin: 22px 0 18px;
  padding: 16px;
  background: var(--card-2);
  border-radius: 12px;
}
.readout {
  display: flex;
  align-items: baseline;
  gap: 8px;
}
#dbVal {
  font-size: 48px;
  font-weight: 800;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}
.unit { font-size: 18px; color: var(--muted); }
.status {
  margin-left: auto;
  font-size: 13px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
}
.status.safe { background: rgba(34, 197, 94, 0.15); color: var(--ok); }
.status.danger { background: rgba(239, 68, 68, 0.18); color: var(--danger); }
.status.muted { background: rgba(139, 92, 246, 0.18); color: var(--accent); }

.bar {
  position: relative;
  height: 18px;
  margin: 14px 0 4px;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.25);
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  width: 0%;
  border-radius: 999px;
  background: var(--ok);
  transition: width 0.08s linear, background 0.2s ease;
}
.bar-fill.warn { background: var(--warn); }
.bar-fill.over { background: var(--danger); }
.thr-mark {
  position: absolute;
  top: -3px;
  width: 3px;
  height: 24px;
  background: #fff;
  box-shadow: 0 0 4px #000;
  border-radius: 2px;
  transform: translateX(-50%);
}
.scale {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--muted);
}
.extra {
  margin-top: 10px;
  font-size: 12px;
  color: var(--muted);
}
.extra b { color: var(--text); }

.calib {
  background: var(--card-2);
  border-radius: 12px;
  padding: 14px;
  margin-bottom: 12px;
}
.calib-note {
  margin: 0 0 10px;
  font-size: 12px;
  color: var(--muted);
  line-height: 1.5;
}
.calib-row { display: flex; gap: 8px; }
.calib-row input {
  flex: 1;
  padding: 9px 12px;
  font-size: 14px;
  border-radius: 10px;
  border: 1px solid rgba(139, 92, 246, 0.3);
  background: var(--card);
  color: var(--text);
  outline: none;
}
.calib-row button { flex: 0 0 auto; padding: 9px 12px; font-size: 13px; }

.ft p {
  margin: 0;
  text-align: center;
  font-size: 11px;
  color: var(--muted);
}

.alarm {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(239, 68, 68, 0.92);
  color: #fff;
  animation: flash 0.6s steps(1) infinite;
}
.alarm.hidden { display: none; }
.alarm-inner { text-align: center; }
.alarm-icon { font-size: 80px; }
.alarm-text { font-size: 32px; font-weight: 900; letter-spacing: 1px; }
.alarm-text .en { display: block; font-size: 16px; font-weight: 700; opacity: 0.9; margin-top: 4px; }
.alarm-db { font-size: 22px; margin-top: 10px; font-variant-numeric: tabular-nums; }
.alarm-ack {
  margin-top: 18px;
  flex: 0 0 auto;
  background: rgba(255, 255, 255, 0.95);
  color: #b91c1c;
  border: none;
  padding: 12px 22px;
  font-size: 16px;
  border-radius: 999px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}
.alarm-ack:hover { filter: brightness(0.95); }
.alarm-hint {
  margin: 12px 0 0;
  font-size: 12px;
  opacity: 0.85;
}

@keyframes flash {
  0% { background: rgba(239, 68, 68, 0.95); }
  50% { background: rgba(180, 30, 30, 0.85); }
  100% { background: rgba(239, 68, 68, 0.95); }
}