:root {
  --bg: #f3f4f6;
  --card: #ffffff;
  --border: #e3e5e9;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-press: #1d4ed8;
  --ok: #22c55e;
  --off: #cbd5e1;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  background: var(--bg);
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif;
  color: #1f2937;
  padding: 32px 16px;
}

.card {
  width: 100%;
  max-width: 480px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px 26px 20px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.06);
}

h1 { font-size: 20px; margin: 0 0 4px; }
.subtitle { color: var(--muted); margin: 0 0 18px; font-size: 13px; line-height: 1.45; }

.device {
  display: flex;
  align-items: center;
  gap: 10px;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
  margin-bottom: 16px;
}
.dot { width: 11px; height: 11px; border-radius: 50%; background: var(--off); flex: 0 0 auto; }
.dot.connected { background: var(--ok); }
.device-info { font-weight: 600; flex: 1 1 auto; font-size: 13px; }

.banner {
  background: #fef3c7;
  border: 1px solid #fde68a;
  color: #92400e;
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 13px;
  margin-bottom: 16px;
}
.hidden { display: none; }

fieldset {
  border: none;
  padding: 0;
  margin: 0;
}
fieldset:disabled { opacity: 0.55; }

.field-label { display: block; font-weight: 600; font-size: 13px; margin: 10px 0 6px; }

.row { display: flex; align-items: center; gap: 10px; }
.row input[type="range"] { flex: 1 1 auto; }
.row input[type="number"] {
  width: 78px;
  padding: 5px 8px;
  border: 1px solid #cbd5e1;
  border-radius: 7px;
  text-align: right;
  font-size: 13px;
}
.unit { color: var(--muted); font-size: 13px; }
.hint { color: var(--muted); font-size: 12px; margin: 4px 0 6px; }

.check {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 13px;
  margin: 14px 0 4px;
  line-height: 1.4;
}

.buttons {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 18px;
}

.btn {
  border: 1px solid #cbd5e1;
  background: #ffffff;
  color: #1f2937;
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}
.btn:hover { background: #f1f5f9; }
.btn:disabled { cursor: default; opacity: 0.6; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-press); }

.status {
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 12.5px;
  min-height: 1.2em;
}
.status.error { color: #b91c1c; }
.status.ok { color: #15803d; }