:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --success: #16a34a;
  --success-light: #f0fdf4;
  --warning: #f59e0b;
  --warning-light: #fffbeb;
  --danger: #dc2626;
  --danger-light: #fef2f2;
  --info: #0891b2;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --white: #ffffff;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1), 0 4px 6px rgba(0,0,0,0.05);
  --radius: 8px;
  --radius-lg: 12px;
  --transition: all 0.2s ease;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  background: var(--gray-100);
  color: var(--gray-800);
  line-height: 1.6;
  min-height: 100vh;
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-hover); }

/* Login */
.login-page { min-height: 100vh; display: flex; align-items: center; justify-content: center; background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); padding: 20px; }
.login-card { background: var(--white); border-radius: var(--radius-lg); padding: 40px; width: 100%; max-width: 420px; box-shadow: var(--shadow-lg); }
.login-card h1 { text-align: center; font-size: 24px; color: var(--gray-900); margin-bottom: 8px; }
.login-card .subtitle { text-align: center; color: var(--gray-500); font-size: 14px; margin-bottom: 32px; }
.login-card .form-group { margin-bottom: 20px; }
.login-card label { display: block; font-size: 14px; font-weight: 500; color: var(--gray-700); margin-bottom: 6px; }
.login-card input { width: 100%; padding: 10px 14px; border: 1px solid var(--gray-300); border-radius: var(--radius); font-size: 15px; transition: var(--transition); }
.login-card input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }
.login-card .btn-login { width: 100%; padding: 12px; background: var(--primary); color: var(--white); border: none; border-radius: var(--radius); font-size: 16px; font-weight: 500; cursor: pointer; transition: var(--transition); margin-top: 8px; }
.login-card .btn-login:hover { background: var(--primary-hover); }
.login-card .btn-login:disabled { opacity: 0.6; cursor: not-allowed; }
.login-error { color: var(--danger); font-size: 13px; margin-top: 12px; text-align: center; display: none; }

/* Layout */
.app-layout { display: flex; min-height: 100vh; }
.sidebar {
  width: 260px; background: var(--gray-900); color: var(--white); display: flex; flex-direction: column;
  position: fixed; top: 0; left: 0; bottom: 0; z-index: 100; transition: transform 0.3s ease;
}
.sidebar-header { padding: 20px 24px; border-bottom: 1px solid rgba(255,255,255,0.1); }
.sidebar-header h2 { font-size: 16px; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.sidebar-header .version { font-size: 11px; color: var(--gray-400); margin-top: 2px; }
.sidebar-nav { flex: 1; padding: 12px 0; overflow-y: auto; }
.sidebar-nav .nav-section { padding: 8px 24px 4px; font-size: 11px; text-transform: uppercase; color: var(--gray-500); letter-spacing: 0.5px; margin-top: 8px; }
.sidebar-nav .nav-item { display: flex; align-items: center; padding: 10px 24px; color: var(--gray-300); font-size: 14px; cursor: pointer; transition: var(--transition); border-left: 3px solid transparent; gap: 12px; }
.sidebar-nav .nav-item:hover { background: rgba(255,255,255,0.05); color: var(--white); }
.sidebar-nav .nav-item.active { background: rgba(37,99,235,0.15); color: var(--white); border-left-color: var(--primary); }
.sidebar-nav .nav-item svg { width: 20px; height: 20px; flex-shrink: 0; }
.sidebar-footer { padding: 16px 24px; border-top: 1px solid rgba(255,255,255,0.1); }
.sidebar-footer .user-info { display: flex; align-items: center; gap: 10px; }
.sidebar-footer .avatar { width: 36px; height: 36px; border-radius: 50%; background: var(--primary); display: flex; align-items: center; justify-content: center; font-size: 14px; font-weight: 600; flex-shrink: 0; }
.sidebar-footer .user-details { overflow: hidden; }
.sidebar-footer .user-name { font-size: 13px; font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.sidebar-footer .user-role { font-size: 11px; color: var(--gray-400); }
.sidebar-footer .btn-logout { margin-top: 12px; width: 100%; padding: 8px; background: rgba(255,255,255,0.1); color: var(--gray-300); border: none; border-radius: var(--radius); font-size: 13px; cursor: pointer; transition: var(--transition); }
.sidebar-footer .btn-logout:hover { background: rgba(220,38,38,0.3); color: var(--white); }
.main-content { flex: 1; margin-left: 260px; display: flex; flex-direction: column; min-height: 100vh; }
.topbar {
  background: var(--white); border-bottom: 1px solid var(--gray-200); padding: 0 24px; height: 60px;
  display: flex; align-items: center; justify-content: space-between; position: sticky; top: 0; z-index: 50;
}
.topbar-left { display: flex; align-items: center; gap: 16px; }
.topbar-left h1 { font-size: 20px; font-weight: 600; color: var(--gray-900); }
.topbar-right { display: flex; align-items: center; gap: 12px; }
.menu-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; color: var(--gray-600); }
.menu-toggle svg { width: 24px; height: 24px; }
.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  color: var(--gray-600);
  margin-right: 8px;
  vertical-align: middle;
}
.page-content {
  flex: 1;
  padding: 24px;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
}

/* Cards */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; margin-bottom: 24px; }
.stat-card { background: var(--white); border-radius: var(--radius-lg); padding: 20px; box-shadow: var(--shadow-sm); border: 1px solid var(--gray-200); transition: var(--transition); }
.stat-card:hover { box-shadow: var(--shadow-md); transform: translateY(-1px); }
.stat-card .stat-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.stat-card .stat-icon { width: 44px; height: 44px; border-radius: var(--radius); display: flex; align-items: center; justify-content: center; }
.stat-card .stat-icon svg { width: 22px; height: 22px; }
.stat-card .stat-icon.blue { background: var(--primary-light); color: var(--primary); }
.stat-card .stat-icon.green { background: var(--success-light); color: var(--success); }
.stat-card .stat-icon.orange { background: var(--warning-light); color: var(--warning); }
.stat-card .stat-icon.red { background: var(--danger-light); color: var(--danger); }
.stat-card .stat-value { font-size: 28px; font-weight: 700; color: var(--gray-900); }
.stat-card .stat-label { font-size: 13px; color: var(--gray-500); margin-top: 2px; }

/* Card container */
.card { background: var(--white); border-radius: var(--radius-lg); box-shadow: var(--shadow-sm); border: 1px solid var(--gray-200); margin-bottom: 20px; }
.card-header { padding: 16px 20px; border-bottom: 1px solid var(--gray-200); display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.card-header h3 { font-size: 16px; font-weight: 600; color: var(--gray-900); }
.card-body { padding: 20px; }
.card-body.no-pad { padding: 0; }

/* Toolbar */
.toolbar { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.toolbar-left { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.toolbar-right { display: flex; align-items: center; gap: 10px; }

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px; border: 1px solid transparent; border-radius: var(--radius); font-size: 14px; font-weight: 500; cursor: pointer; transition: var(--transition); white-space: nowrap; text-decoration: none; }
.btn svg { width: 16px; height: 16px; }
.btn-primary { background: var(--primary); color: var(--white); border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-hover); }
.btn-success { background: var(--success); color: var(--white); }
.btn-success:hover { background: #15803d; }
.btn-warning { background: var(--warning); color: var(--white); }
.btn-warning:hover { background: #d97706; }
.btn-danger { background: var(--danger); color: var(--white); }
.btn-danger:hover { background: #b91c1c; }
.btn-outline { background: var(--white); color: var(--gray-700); border-color: var(--gray-300); }
.btn-outline:hover { background: var(--gray-50); border-color: var(--gray-400); }
.btn-sm { padding: 5px 10px; font-size: 13px; }
.btn-sm svg { width: 14px; height: 14px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Inputs */
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13px; font-weight: 500; color: var(--gray-700); margin-bottom: 4px; }
.form-group label .required { color: var(--danger); }
.form-control { width: 100%; padding: 8px 12px; border: 1px solid var(--gray-300); border-radius: var(--radius); font-size: 14px; transition: var(--transition); background: var(--white); color: var(--gray-800); }
  .form-control:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }
select.form-control { appearance: auto; }
textarea.form-control { resize: vertical; min-height: 80px; }
.form-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }
.search-input { position: relative; }
.search-input input { padding-left: 36px; }
.search-input svg { position: absolute; left: 10px; top: 50%; transform: translateY(-50%); width: 16px; height: 16px; color: var(--gray-400); }

/* Table */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
table th { background: var(--gray-50); padding: 10px 16px; text-align: left; font-size: 12px; font-weight: 600; color: var(--gray-500); text-transform: uppercase; letter-spacing: 0.5px; border-bottom: 1px solid var(--gray-200); white-space: nowrap; }
table td { padding: 12px 16px; border-bottom: 1px solid var(--gray-100); font-size: 14px; color: var(--gray-700); }
table tbody tr { transition: var(--transition); }
table tbody tr:hover { background: var(--gray-50); }
.table-actions { display: flex; gap: 6px; }

/* Badges */
.badge { display: inline-flex; align-items: center; padding: 2px 10px; border-radius: 999px; font-size: 12px; font-weight: 500; }
.badge-blue { background: var(--primary-light); color: var(--primary); }
.badge-green { background: var(--success-light); color: var(--success); }
.badge-orange { background: var(--warning-light); color: var(--warning); }
.badge-red { background: var(--danger-light); color: var(--danger); }
.badge-gray { background: var(--gray-100); color: var(--gray-600); }

/* Pagination */
.pagination { display: flex; justify-content: space-between; align-items: center; padding: 16px 20px; border-top: 1px solid var(--gray-200); flex-wrap: wrap; gap: 12px; }
.pagination-info { font-size: 13px; color: var(--gray-500); }
.pagination-btns { display: flex; gap: 4px; }
.pagination-btns button { padding: 6px 12px; border: 1px solid var(--gray-300); background: var(--white); border-radius: var(--radius); font-size: 13px; cursor: pointer; transition: var(--transition); }
.pagination-btns button:hover:not(:disabled) { background: var(--gray-50); border-color: var(--gray-400); }
.pagination-btns button.active { background: var(--primary); color: var(--white); border-color: var(--primary); }
.pagination-btns button:disabled { opacity: 0.4; cursor: not-allowed; }

/* Modal */
.modal-overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); display: flex; align-items: center; justify-content: center; z-index: 1000; padding: 20px; opacity: 0; visibility: hidden; transition: all 0.2s ease; }
.modal-overlay.show { opacity: 1; visibility: visible; }
.modal { background: var(--white); border-radius: var(--radius-lg); width: 100%; max-width: 600px; max-height: 90vh; overflow-y: auto; box-shadow: var(--shadow-lg); transform: scale(0.95); transition: transform 0.2s ease; }
.modal-overlay.show .modal { transform: scale(1); }
.modal-header { padding: 16px 20px; border-bottom: 1px solid var(--gray-200); display: flex; justify-content: space-between; align-items: center; }
.modal-header h3 { font-size: 17px; font-weight: 600; }
.modal-close { background: none; border: none; cursor: pointer; padding: 4px; color: var(--gray-400); border-radius: var(--radius); }
.modal-close:hover { background: var(--gray-100); color: var(--gray-600); }
.modal-close svg { width: 20px; height: 20px; }
.modal-body { padding: 20px; }
.modal-footer { padding: 16px 20px; border-top: 1px solid var(--gray-200); display: flex; justify-content: flex-end; gap: 10px; }

/* Toast */
.toast-container { position: fixed; top: 20px; right: 20px; z-index: 2000; display: flex; flex-direction: column; gap: 8px; }
.toast { padding: 12px 20px; border-radius: var(--radius); color: var(--white); font-size: 14px; box-shadow: var(--shadow-lg); animation: slideIn 0.3s ease; max-width: 400px; }
.toast-success { background: var(--success); }
.toast-error { background: var(--danger); }
.toast-info { background: var(--info); }
@keyframes slideIn { from { transform: translateX(100%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }

/* Device detail */
.detail-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }
.detail-item { padding: 12px; background: var(--gray-50); border-radius: var(--radius); }
.detail-item .label { font-size: 12px; color: var(--gray-500); margin-bottom: 4px; }
.detail-item .value { font-size: 14px; color: var(--gray-800); font-weight: 500; word-break: break-all; }

/* Customer query */
.query-result { margin-top: 16px; }
.device-card { border: 1px solid var(--gray-200); border-radius: var(--radius-lg); padding: 20px; margin-bottom: 16px; }
.device-card h4 { font-size: 16px; color: var(--gray-900); margin-bottom: 12px; }
.device-card .meta { display: flex; flex-wrap: wrap; gap: 16px; margin-bottom: 12px; }
.device-card .meta-item { font-size: 13px; color: var(--gray-600); }
.device-card .meta-item strong { color: var(--gray-800); }
.maintenance-timeline { border-left: 2px solid var(--gray-200); padding-left: 16px; margin-top: 12px; }
.maintenance-timeline .timeline-item { position: relative; padding: 0 0 16px 16px; }
.maintenance-timeline .timeline-item::before { content: ''; position: absolute; left: -6px; top: 4px; width: 10px; height: 10px; border-radius: 50%; background: var(--primary); }
.maintenance-timeline .timeline-date { font-size: 12px; color: var(--gray-500); margin-bottom: 2px; }
.maintenance-timeline .timeline-type { display: inline-block; padding: 1px 8px; border-radius: 4px; font-size: 11px; font-weight: 500; margin-bottom: 4px; }
.maintenance-timeline .timeline-desc { font-size: 14px; color: var(--gray-700); }

/* Empty state */
.empty-state { text-align: center; padding: 48px 20px; color: var(--gray-400); }
.empty-state svg { width: 64px; height: 64px; margin-bottom: 16px; opacity: 0.5; }
.empty-state p { font-size: 15px; }

/* Loading */
.loading { display: flex; align-items: center; justify-content: center; padding: 40px; }
.spinner { width: 32px; height: 32px; border: 3px solid var(--gray-200); border-top-color: var(--primary); border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* Responsive */
@media (max-width: 768px) {
  html, body {
    height: 100%;
    overflow: hidden;
  }
  .app-layout {
    width: 100%;
    height: 100%;
    overflow: hidden;
    position: relative;
  }
  .sidebar {
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .main-content {
    margin-left: 0;
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    display: flex;
    flex-direction: column;
  }
  .topbar {
    position: fixed !important;
    top: 0;
    left: 0;
    right: 0;
    height: 60px;
    z-index: 50;
    flex-shrink: 0;
  }
  .page-content {
    padding: 16px;
    padding-top: 76px;
    padding-bottom: 16px;
    height: calc(100% - 60px);
    overflow-y: auto;
    overflow-x: hidden;
    -webkit-overflow-scrolling: touch;
  }
  .table-wrap {
    overflow-x: auto !important;
    -webkit-overflow-scrolling: touch;
  }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .stat-card { padding: 14px; }
  .stat-card .stat-value { font-size: 22px; }
  .card-header { padding: 12px 16px; }
  .card-body { padding: 16px; }
  .toolbar { flex-direction: column; align-items: stretch; }
  .toolbar-left, .toolbar-right { flex-wrap: wrap; }
  .form-row { grid-template-columns: 1fr; }
  .detail-grid { grid-template-columns: 1fr; }
  .login-card { padding: 28px 24px; }
  table td, table th { padding: 8px 12px; font-size: 13px; }
  .modal { max-width: 100%; margin: 10px; }
}
@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr; }
  .stat-card .stat-icon { width: 36px; height: 36px; }
  .stat-card .stat-icon.svg { width: 18px; height: 18px; }
}

/* Overlay for mobile sidebar */
.sidebar-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.4); z-index: 99; }
.sidebar-overlay.show { display: block; }

/* Selection input with picker button */
.selection-input-wrap {
  display: flex;
  align-items: center;
  gap: 0;
}
.selection-input-wrap .form-control {
  border-radius: var(--radius) 0 0 var(--radius);
  border-right: none;
  flex: 1;
  width: auto;
}
.selection-input-wrap .form-control:focus {
  border-right: 1px solid var(--gray-300);
  margin-right: -1px;
}
.picker-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 38px;
  border: 1px solid var(--gray-300);
  border-left: none;
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--gray-50);
  cursor: pointer;
  color: var(--gray-500);
  transition: var(--transition);
  flex-shrink: 0;
}
.picker-btn:hover {
  background: var(--gray-100);
  color: var(--primary);
}
.picker-btn svg {
  width: 16px;
  height: 16px;
}

/* Picker list items */
.picker-list {
  max-height: 300px;
  overflow-y: auto;
}
.picker-item {
  padding: 10px 12px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  cursor: pointer;
  transition: var(--transition);
  margin-bottom: 6px;
}
.picker-item:hover {
  background: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary);
}
.picker-item .item-title {
  font-size: 14px;
  font-weight: 500;
  color: var(--gray-800);
}
.picker-item:hover .item-title {
  color: var(--primary);
}
.picker-item .item-subtitle {
  font-size: 12px;
  color: var(--gray-500);
  margin-top: 2px;
}
.picker-item:hover .item-subtitle {
  color: var(--primary);
}

/* Config textarea auto-height */
.config-textarea {
  min-height: 38px;
  max-height: 300px;
  line-height: 1.5;
  overflow-y: hidden;
}

/* Modal for maintenance form */
#maintenanceModal .modal {
  max-width: 700px;
}