:root {
  --bg: #f5f6fa;
  --card: #ffffff;
  --text: #1a1d29;
  --muted: #6b7280;
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --border: #e5e7eb;
  --danger: #dc2626;
  --ok: #16a34a;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

.topbar {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 10;
}
.brand { font-weight: 700; font-size: 18px; color: var(--primary); display: flex; gap: 8px; align-items: center; }
.brand span { color: var(--text); }

.container { max-width: 1080px; margin: 0 auto; padding: 24px; }
.container-narrow { max-width: 420px; margin: 8vh auto; padding: 24px; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
}

h1 { font-size: 24px; margin: 0 0 4px; }
h2 { font-size: 18px; margin: 0 0 12px; }
.muted { color: var(--muted); font-size: 14px; }

label { display: block; font-size: 13px; font-weight: 600; margin: 12px 0 4px; }
input, select, textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  background: #fff;
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--primary); border-color: var(--primary); }
textarea { min-height: 90px; resize: vertical; }

.btn {
  display: inline-flex; align-items: center; gap: 6px; justify-content: center;
  padding: 10px 16px;
  border: none; border-radius: 8px;
  background: var(--primary); color: #fff;
  font-size: 14px; font-weight: 600; cursor: pointer;
  transition: background .15s;
}
.btn:hover { background: var(--primary-dark); }
.btn:disabled { opacity: .6; cursor: not-allowed; }
.btn-secondary { background: #fff; color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover { background: #f3f4f6; }
.btn-danger { background: var(--danger); }
.btn-danger:hover { background: #b91c1c; }
.btn-sm { padding: 6px 10px; font-size: 13px; }
.btn-block { width: 100%; }

.row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.space-between { justify-content: space-between; }
.mt { margin-top: 16px; }
.mb { margin-bottom: 16px; }

.error { color: var(--danger); font-size: 14px; margin-top: 8px; min-height: 18px; }
.success { color: var(--ok); font-size: 14px; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; }

.qr-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); padding: 16px; display: flex; flex-direction: column; gap: 10px; }
.qr-card img { width: 110px; height: 110px; align-self: center; border: 1px solid var(--border); border-radius: 8px; }
.qr-card .name { font-weight: 600; }
.badge { display: inline-block; font-size: 11px; padding: 2px 8px; border-radius: 999px; background: #eef2ff; color: var(--primary); font-weight: 600; }
.badge-static { background: #f3f4f6; color: var(--muted); }
.badge-off { background: #fef2f2; color: var(--danger); }

.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px,1fr)); gap: 12px; }
.stat { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }
.stat .num { font-size: 28px; font-weight: 700; }
.stat .lbl { color: var(--muted); font-size: 13px; }

table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--border); }
th { color: var(--muted); font-weight: 600; font-size: 12px; text-transform: uppercase; }

.modal-bg { position: fixed; inset: 0; background: rgba(0,0,0,.4); display: none; align-items: center; justify-content: center; padding: 16px; z-index: 50; }
.modal-bg.open { display: flex; }
.modal { background: #fff; border-radius: var(--radius); padding: 24px; width: 100%; max-width: 480px; max-height: 90vh; overflow: auto; }

.hidden { display: none !important; }
.chart-box { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }
canvas { max-width: 100%; }