:root {
  --sidebar-bg: #0f172a;
  --sidebar-border: #1e293b;
  --sidebar-text: #94a3b8;
  --sidebar-active-bg: #1d4ed8;
  --sidebar-active-text: #fff;
  --sidebar-hover-bg: #1e293b;
  --sidebar-width: 240px;
  --topbar-height: 60px;
  --content-bg: #f1f5f9;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --text-primary: #0f172a;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --info: #06b6d4;
  --radius: 8px;
  --shadow: 0 1px 3px 0 rgb(0 0 0 / .1), 0 1px 2px -1px rgb(0 0 0 / .1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / .1), 0 2px 4px -2px rgb(0 0 0 / .1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--content-bg);
  color: var(--text-primary);
  font-size: 14px;
  line-height: 1.5;
}

/* ── Layout ── */
.layout { display: flex; min-height: 100vh; }

.sidebar {
  width: var(--sidebar-width);
  background: var(--sidebar-bg);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0; bottom: 0;
  z-index: 100;
  border-right: 1px solid var(--sidebar-border);
}

.sidebar-logo {
  height: var(--topbar-height);
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 0 18px;
  border-bottom: 1px solid var(--sidebar-border);
  text-decoration: none;
  flex-shrink: 0;
}

.sidebar-logo img { flex-shrink: 0; width: 34px; height: 34px; }

.sidebar-logo-text { display: flex; flex-direction: column; gap: 1px; }
.sidebar-logo-name {
  color: #fff;
  font-weight: 800;
  font-size: 15px;
  letter-spacing: -.02em;
  line-height: 1.1;
}
.sidebar-logo-name span { color: #60a5fa; }
.sidebar-logo-by {
  color: #475569;
  font-size: 9.5px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: .08em;
  line-height: 1;
}

.sidebar-nav { flex: 1; padding: 16px 12px; }

.nav-section-title {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--sidebar-text);
  padding: 8px 10px 4px;
  margin-top: 12px;
}

.nav-section-title:first-child { margin-top: 0; }

.nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 10px;
  border-radius: 6px;
  color: var(--sidebar-text);
  text-decoration: none;
  font-size: 13.5px;
  transition: background .15s, color .15s;
  margin-bottom: 2px;
}

.nav-link:hover { background: var(--sidebar-hover-bg); color: #e2e8f0; }
.nav-link.active { background: var(--sidebar-active-bg); color: var(--sidebar-active-text); }
.nav-link svg { flex-shrink: 0; opacity: .8; }
.nav-link.active svg { opacity: 1; }

.sidebar-footer {
  padding: 16px;
  border-top: 1px solid var(--sidebar-border);
}

.mqtt-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--sidebar-text);
}

.mqtt-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--text-muted);
  flex-shrink: 0;
  transition: background .3s;
}

.mqtt-dot.connected { background: var(--success); box-shadow: 0 0 6px var(--success); }
.mqtt-dot.disconnected { background: var(--danger); }

.main-wrap { margin-left: var(--sidebar-width); flex: 1; display: flex; flex-direction: column; min-height: 100vh; }

/* ── Top bar ── */
.topbar {
  height: var(--topbar-height);
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar-left { display: flex; align-items: center; gap: 8px; }

.breadcrumb { display: flex; align-items: center; gap: 6px; font-size: 13px; color: var(--text-secondary); }
.breadcrumb a { color: var(--text-secondary); text-decoration: none; }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb-sep { color: var(--text-muted); }
.breadcrumb-current { color: var(--text-primary); font-weight: 500; }

.topbar-right { display: flex; align-items: center; gap: 12px; }

.device-count-badge {
  background: var(--content-bg);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 4px 12px;
  font-size: 12px;
  color: var(--text-secondary);
  font-weight: 500;
}

/* ── Content ── */
.content { flex: 1; padding: 24px; }

/* ── Cards ── */
.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.card-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.card-title { font-weight: 600; font-size: 15px; color: var(--text-primary); }
.card-subtitle { font-size: 13px; color: var(--text-secondary); margin-top: 2px; }

/* ── Stats row ── */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 16px; margin-bottom: 24px; }

.stat-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 20px;
  box-shadow: var(--shadow);
}

.stat-label { font-size: 12px; font-weight: 500; text-transform: uppercase; letter-spacing: .06em; color: var(--text-muted); }
.stat-value { font-size: 28px; font-weight: 700; color: var(--text-primary); margin-top: 4px; }
.stat-sub { font-size: 12px; color: var(--text-secondary); margin-top: 4px; }

/* ── Table ── */
.table-wrap { overflow-x: auto; }

table { width: 100%; border-collapse: collapse; }

thead th {
  padding: 11px 16px;
  text-align: left;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
  background: #fafbfc;
}

thead th:first-child { padding-left: 20px; }

tbody tr { transition: background .1s; }
tbody tr:hover > td { background: #f8fafc; }
tbody tr.expanded > td { background: #f0f4ff; }

tbody td {
  padding: 13px 16px;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}

tbody td:first-child { padding-left: 20px; }

tr.expand-row td { padding: 0; border-bottom: 1px solid var(--border); }
tr.expand-row.hidden { display: none; }

.expand-content {
  padding: 20px;
  background: #f8fafc;
  border-top: 2px solid var(--primary);
}

/* ── Status dot ── */
.status-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
}

.status-dot.online { background: var(--success); box-shadow: 0 0 6px rgb(16 185 129 / .5); }
.status-dot.stale  { background: var(--warning); box-shadow: 0 0 6px rgb(245 158 11 / .5); animation: pulse-stale 1.4s ease-in-out infinite; }
.status-dot.offline { background: var(--danger); }
.status-dot.unknown { background: var(--text-muted); }

@keyframes pulse-stale {
  0%, 100% { opacity: 1; }
  50%       { opacity: .4; }
}

/* ── Badges ── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
}

.badge-gen1 { background: #fef3c7; color: #92400e; }
.badge-gen2 { background: #dbeafe; color: #1e40af; }
.badge-gen3 { background: #ede9fe; color: #5b21b6; }
.badge-online  { background: #d1fae5; color: #065f46; }
.badge-stale   { background: #fef3c7; color: #92400e; }
.badge-offline { background: #fee2e2; color: #991b1b; }
.badge-on { background: #d1fae5; color: #065f46; }
.badge-off { background: #fee2e2; color: #991b1b; }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background .15s, box-shadow .15s, border-color .15s;
  text-decoration: none;
  white-space: nowrap;
  line-height: 1;
}

.btn-primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-hover); border-color: var(--primary-hover); }

.btn-ghost { background: transparent; color: var(--text-secondary); border-color: transparent; }
.btn-ghost:hover { background: var(--content-bg); color: var(--text-primary); }

.btn-outline { background: #fff; color: var(--text-primary); border-color: var(--border); }
.btn-outline:hover { background: var(--content-bg); border-color: #cbd5e1; }

.btn-danger { background: var(--danger); color: #fff; border-color: var(--danger); }
.btn-success { background: var(--success); color: #fff; border-color: var(--success); }

.btn-sm { padding: 5px 10px; font-size: 12px; }
.btn-icon { padding: 7px; }

.btn-group { display: flex; gap: 6px; }

/* ── Expand toggle ── */
.expand-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  padding: 4px;
  border-radius: 4px;
  transition: background .15s, color .15s;
}

.expand-btn:hover { background: var(--content-bg); color: var(--primary); }
.expand-btn svg { transition: transform .2s; }
.expand-btn.open svg { transform: rotate(180deg); }

/* ── Topic data grid ── */
.topic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 8px; }

.topic-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 14px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.topic-key { font-size: 11px; font-weight: 600; color: var(--text-muted); font-family: monospace; }
.topic-val { font-size: 13px; color: var(--text-primary); word-break: break-all; font-family: monospace; }

/* ── Device detail ── */
.device-header {
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  padding: 24px;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 20px;
  box-shadow: var(--shadow);
}

.device-icon {
  width: 56px; height: 56px;
  background: #eff6ff;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--primary);
}

.device-header-info { flex: 1; min-width: 0; }
.device-header-id { font-size: 20px; font-weight: 700; color: var(--text-primary); }
.device-header-meta { display: flex; align-items: center; gap: 10px; margin-top: 6px; flex-wrap: wrap; }

.detail-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; margin-bottom: 20px; }

.detail-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  box-shadow: var(--shadow);
}

.detail-card-label { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: .06em; color: var(--text-muted); }
.detail-card-value { font-size: 22px; font-weight: 700; color: var(--text-primary); margin-top: 4px; }
.detail-card-unit { font-size: 13px; font-weight: 400; color: var(--text-secondary); }

/* ── Tabs ── */
.tabs { display: flex; gap: 2px; border-bottom: 2px solid var(--border); margin-bottom: 20px; }

.tab-btn {
  padding: 10px 18px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-secondary);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  cursor: pointer;
  transition: color .15s, border-color .15s;
}

.tab-btn:hover { color: var(--text-primary); }
.tab-btn.active { color: var(--primary); border-bottom-color: var(--primary); }

.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ── Command form ── */
.cmd-form { display: flex; flex-direction: column; gap: 14px; max-width: 560px; }

.form-group { display: flex; flex-direction: column; gap: 5px; }

.form-label { font-size: 12px; font-weight: 600; color: var(--text-secondary); text-transform: uppercase; letter-spacing: .05em; }

.form-input, .form-select, .form-textarea {
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13.5px;
  color: var(--text-primary);
  background: #fff;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
  font-family: inherit;
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgb(37 99 235 / .1);
}

.form-textarea { min-height: 100px; resize: vertical; font-family: monospace; font-size: 13px; }

.quick-cmds { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 8px; }

/* ── Form toggle switch ── */
.form-toggle { display: flex; align-items: center; gap: 10px; cursor: pointer; user-select: none; }
.form-toggle input[type="checkbox"] {
  appearance: none; -webkit-appearance: none;
  width: 36px; height: 20px;
  background: var(--border); border-radius: 10px;
  cursor: pointer; flex-shrink: 0;
  transition: background .2s;
  position: relative;
}
.form-toggle input[type="checkbox"]:checked { background: var(--primary); }
.form-toggle input[type="checkbox"]::after {
  content: ''; position: absolute;
  top: 2px; left: 2px;
  width: 16px; height: 16px;
  background: #fff; border-radius: 50%;
  box-shadow: 0 1px 3px rgb(0 0 0 / .2);
  transition: left .18s;
}
.form-toggle input[type="checkbox"]:checked::after { left: 18px; }
.form-toggle span { font-size: 13.5px; color: var(--text-primary); }

/* ── Form section divider ── */
.form-section {
  font-size: 11px; font-weight: 700; letter-spacing: .08em;
  text-transform: uppercase; color: var(--text-muted);
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border);
  margin-top: 4px;
}

/* ── Form 2-col grid ── */
.form-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

.quick-cmd-btn {
  padding: 5px 12px;
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 12px;
  background: #fff;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all .15s;
}

.quick-cmd-btn:hover { background: #eff6ff; border-color: var(--primary); color: var(--primary); }

/* ── Response box ── */
.response-box {
  background: #0f172a;
  color: #e2e8f0;
  border-radius: 6px;
  padding: 14px 16px;
  font-family: monospace;
  font-size: 12.5px;
  white-space: pre-wrap;
  word-break: break-all;
  max-height: 300px;
  overflow-y: auto;
  min-height: 60px;
}

.response-box.empty { color: #475569; }

/* ── Search / filter bar ── */
.filter-bar { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }

.search-input-wrap { position: relative; flex: 1; min-width: 180px; max-width: 300px; }
.search-icon { position: absolute; left: 10px; top: 50%; transform: translateY(-50%); color: var(--text-muted); pointer-events: none; }
.search-input { width: 100%; padding: 8px 12px 8px 34px; border: 1px solid var(--border); border-radius: 6px; font-size: 13.5px; outline: none; transition: border-color .15s; }
.search-input:focus { border-color: var(--primary); }

.filter-select { padding: 8px 12px; border: 1px solid var(--border); border-radius: 6px; font-size: 13px; background: #fff; outline: none; color: var(--text-primary); }

/* ── Empty state ── */
.empty-state {
  padding: 60px 20px;
  text-align: center;
  color: var(--text-muted);
}

.empty-state svg { margin: 0 auto 16px; opacity: .3; }
.empty-state-title { font-size: 16px; font-weight: 600; color: var(--text-secondary); margin-bottom: 6px; }
.empty-state-sub { font-size: 13px; }

/* ── Loading ── */
.loading-row td { text-align: center; padding: 40px; color: var(--text-muted); }

.spinner {
  width: 20px; height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin .7s linear infinite;
  display: inline-block;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* ── Misc ── */
.text-mono { font-family: monospace; font-size: 12px; }
.text-right { text-align: right; }
.flex { display: flex; }
.items-center { align-items: center; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.mt-1 { margin-top: 4px; }
.mt-2 { margin-top: 8px; }
.mt-3 { margin-top: 12px; }
.mb-4 { margin-bottom: 16px; }
.fw-600 { font-weight: 600; }
.text-sm { font-size: 12px; }
.text-muted { color: var(--text-muted); }
.text-secondary { color: var(--text-secondary); }

.alert {
  padding: 10px 14px;
  border-radius: 6px;
  font-size: 13px;
  border: 1px solid;
}

.alert-success { background: #d1fae5; border-color: #6ee7b7; color: #065f46; }
.alert-error { background: #fee2e2; border-color: #fca5a5; color: #991b1b; }
.alert-info { background: #e0f2fe; border-color: #7dd3fc; color: #0369a1; }

.pulse {
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: .4; }
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .sidebar { transform: translateX(-100%); }
  .main-wrap { margin-left: 0; }
}