:root {
  --mbu-blue: #1a5fa8;
  --mbu-blue-dark: #124a86;
  --readout-bg: #0e1a2b;
  --readout-fg: #4fc3f7;
  --green: #2e9e5b;
  --border: #e0e6ee;
  --bg: #d7e8f7;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  font-family: -apple-system, "Segoe UI", Roboto, sans-serif;
  display: flex;
  justify-content: center;
  padding: 40px 16px;
}

.card {
  width: 100%;
  max-width: 560px;
  background: #fff;
  border-radius: 12px;
  padding: 32px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
}

.brand {
  text-align: center;
  font-weight: 800;
  font-size: 22px;
  color: var(--mbu-blue-dark);
  letter-spacing: 1px;
}

h1 {
  text-align: center;
  color: var(--mbu-blue);
  font-size: 20px;
  margin: 4px 0 24px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 16px;
}

h2 {
  color: var(--mbu-blue-dark);
  font-size: 16px;
  margin-top: 32px;
}

.field {
  margin-bottom: 16px;
}

.field label {
  display: block;
  font-weight: 600;
  color: #333;
  margin-bottom: 6px;
  font-size: 14px;
}

select, input[type="text"], input[type="number"] {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
}

.readout {
  background: var(--readout-bg);
  color: var(--readout-fg);
  border-radius: 8px;
  text-align: center;
  padding: 28px 12px;
  font-family: "SF Mono", "Menlo", monospace;
  font-size: 42px;
  letter-spacing: 2px;
  margin-top: 8px;
}

.status {
  text-align: center;
  font-size: 13px;
  color: #6b7280;
  margin: 8px 0 16px;
}

.actions {
  display: flex;
  justify-content: center;
  margin-bottom: 8px;
}

.btn-save {
  background: var(--green);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 12px 48px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
}

.btn-save:hover { opacity: 0.9; }
.btn-save:disabled { opacity: 0.5; cursor: not-allowed; }

.history-table, .device-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
  font-size: 13px;
}

.history-table th, .history-table td,
.device-table th, .device-table td {
  border-bottom: 1px solid var(--border);
  padding: 8px 6px;
  text-align: left;
}

.history-table th, .device-table th {
  color: var(--mbu-blue-dark);
}

.empty { color: #9ca3af; text-align: center; }

.device-manager {
  margin-top: 28px;
  border-top: 1px solid var(--border);
  padding-top: 16px;
}

.device-manager summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--mbu-blue);
}

.device-table input { padding: 4px 6px; font-size: 13px; }

.btn-small {
  padding: 4px 10px;
  font-size: 12px;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: #f5f7fa;
  cursor: pointer;
  margin-right: 4px;
}

.btn-danger { color: #b91c1c; border-color: #f3c2c2; }

.add-device {
  display: grid;
  grid-template-columns: 2fr 2fr 1fr auto;
  gap: 6px;
  margin-top: 12px;
}