:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --success: #16a34a;
  --success-light: #dcfce7;
  --warning: #d97706;
  --warning-light: #fef3c7;
  --danger: #dc2626;
  --danger-light: #fee2e2;
  --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;
  --radius: 12px;
  --radius-sm: 8px;
  --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);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--gray-100);
  color: var(--gray-800);
  -webkit-font-smoothing: antialiased;
}

/* ===== LOGIN ===== */
.login-page {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
  padding: 20px;
}
.login-card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 40px 32px;
  width: 100%;
  max-width: 380px;
}
.login-card h1 {
  text-align: center;
  font-size: 24px;
  margin-bottom: 8px;
  color: var(--gray-900);
}
.login-card .subtitle {
  text-align: center;
  color: var(--gray-500);
  font-size: 14px;
  margin-bottom: 28px;
}

/* ===== FORMS ===== */
.form-group { margin-bottom: 16px; }
.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: 6px;
}
.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  font-size: 15px;
  outline: none;
  transition: border-color .2s, box-shadow .2s;
  background: #fff;
  color: var(--gray-800);
}
.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}
.form-textarea { resize: vertical; min-height: 70px; }

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 18px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: background .2s, opacity .2s, transform .1s;
  text-decoration: none;
  white-space: nowrap;
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-success { background: var(--success); color: #fff; }
.btn-success:hover { background: #15803d; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { background: #b91c1c; }
.btn-outline { background: transparent; border: 1px solid var(--gray-300); color: var(--gray-600); }
.btn-outline:hover { background: var(--gray-100); }
.btn-sm { padding: 6px 12px; font-size: 13px; }
.torch-btn { min-width: 80px; transition: all 0.2s; }
.torch-btn.torch-on { background: var(--warning-light); border-color: var(--warning); color: var(--warning); }
.btn-block { width: 100%; }
.btn-icon-scan {
  background: none; border: none; cursor: pointer; font-size: 16px;
  padding: 0 4px; vertical-align: middle; opacity: 0.6; transition: opacity 0.2s;
}
.btn-icon-scan:hover { opacity: 1; }
.table td, .table th { word-break: break-all; max-width: 200px; }

/* ===== APP LAYOUT ===== */
.app { display: flex; min-height: 100vh; }
.sidebar {
  width: 220px;
  background: var(--gray-900);
  color: var(--gray-300);
  flex-shrink: 0;
  transition: transform .3s;
  z-index: 100;
  display: flex;
  flex-direction: column;
}
.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid var(--gray-800);
}
.sidebar-header h2 { font-size: 18px; color: #fff; }
.sidebar-header p { font-size: 12px; color: var(--gray-500); margin-top: 2px; }
.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 20px;
  cursor: pointer;
  transition: background .2s, color .2s;
  border: none;
  background: none;
  color: var(--gray-400);
  font-size: 15px;
  width: 100%;
  text-align: left;
}
.nav-item:hover { background: var(--gray-800); color: #fff; }
.nav-item.active { background: var(--primary); color: #fff; }
.nav-item .nav-icon { width: 20px; text-align: center; }
.nav-badge {
  margin-left: auto;
  background: var(--danger);
  color: #fff;
  font-size: 11px;
  padding: 2px 7px;
  border-radius: 10px;
  min-width: 18px;
  text-align: center;
}
.sidebar-footer {
  margin-top: auto;
  padding: 16px 20px;
  border-top: 1px solid var(--gray-800);
  font-size: 13px;
}
.sidebar-footer .user-info { color: var(--gray-400); margin-bottom: 8px; }
.sidebar-footer .user-info strong { color: #fff; display: block; }

.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 24px;
  background: #fff;
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 50;
}
.topbar h1 { font-size: 18px; color: var(--gray-900); }
.topbar .spacer { flex: 1; }
.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--gray-700);
}
.content { padding: 24px; flex: 1; }

/* ===== DASHBOARD ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}
.stat-card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
}
.stat-card .stat-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 12px;
}
.stat-card .stat-label { font-size: 13px; color: var(--gray-500); margin-bottom: 4px; }
.stat-card .stat-value { font-size: 26px; font-weight: 700; color: var(--gray-900); }

/* ===== CARD / TABLE ===== */
.card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.card-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  gap: 12px;
}
.card-header h3 { font-size: 16px; color: var(--gray-900); flex: 1; }
.card-body { padding: 20px; }

.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th {
  text-align: left;
  padding: 10px 16px;
  font-size: 13px;
  font-weight: 600;
  color: var(--gray-500);
  border-bottom: 2px solid var(--gray-200);
  white-space: nowrap;
}
td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--gray-100);
  font-size: 14px;
  white-space: nowrap;
}
tr:hover td { background: var(--gray-50); }

/* ===== BADGES ===== */
.badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
}
.badge-success { background: var(--success-light); color: var(--success); }
.badge-warning { background: var(--warning-light); color: var(--warning); }
.badge-danger { background: var(--danger-light); color: var(--danger); }
.badge-gray { background: var(--gray-100); color: var(--gray-500); }

/* ===== MODAL ===== */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.5);
  z-index: 200;
  align-items: center;
  justify-content: center;
  padding: 16px;
}
.modal-overlay.active { display: flex; }
.modal {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 480px;
  max-height: 90vh;
  overflow-y: auto;
}
.modal-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.modal-header h3 { font-size: 17px; color: var(--gray-900); }
.modal-close {
  background: none; border: none; font-size: 22px;
  cursor: pointer; color: var(--gray-400); line-height: 1;
}
.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: 300;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.toast {
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 14px;
  box-shadow: var(--shadow-md);
  animation: slideIn .3s ease;
  max-width: 360px;
}
.toast-success { background: var(--success); }
.toast-error { background: var(--danger); }
.toast-info { background: var(--primary); }
@keyframes slideIn {
  from { transform: translateX(120%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

/* ===== SEARCH BAR ===== */
.search-bar {
  display: flex;
  gap: 10px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.search-bar .form-input { flex: 1; min-width: 180px; }

/* ===== EMPTY STATE ===== */
.empty-state {
  text-align: center;
  padding: 48px 20px;
  color: var(--gray-400);
}
.empty-state .empty-icon { font-size: 48px; margin-bottom: 12px; }
.empty-state p { font-size: 15px; }

/* ===== STOCK LEVEL ===== */
.stock-level { display: flex; align-items: center; gap: 8px; }
.stock-bar {
  width: 60px;
  height: 6px;
  border-radius: 3px;
  background: var(--gray-200);
  overflow: hidden;
}
.stock-bar-fill { height: 100%; border-radius: 3px; }

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    top: 0; left: 0; bottom: 0;
    transform: translateX(-100%);
  }
  .sidebar.open { transform: translateX(0); }
  .menu-toggle { display: block; }
  .content { padding: 16px; }
  .topbar { padding: 10px 16px; }
  .topbar h1 { font-size: 16px; }
  .stat-card { padding: 16px; }
  .stat-card .stat-value { font-size: 22px; }
  .modal { max-width: 100%; }
  th, td { padding: 8px 10px; font-size: 13px; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
  .stat-card { padding: 12px; }
  .stat-card .stat-value { font-size: 18px; }
  .stat-card .stat-label { font-size: 11px; }
  .stat-card .stat-icon { width: 36px; height: 36px; font-size: 18px; }
  .btn { padding: 8px 14px; font-size: 14px; }
}

.overlay-backdrop {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.3);
  z-index: 99;
}
.overlay-backdrop.active { display: block; }

.page-section { display: none; }
.page-section.active { display: block; }

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

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 600px) { .two-col { grid-template-columns: 1fr; } }

.muted { color: var(--gray-500); font-size: 13px; }
.text-danger { color: var(--danger); }
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.font-bold { font-weight: 600; }
.mt-16 { margin-top: 16px; }
.mb-16 { margin-bottom: 16px; }

.alert { padding: 10px 14px; border-radius: 8px; font-size: 14px; margin-bottom: 8px; }
.alert-danger { background: #fef2f2; color: var(--danger); border: 1px solid #fecaca; }
.alert-warning { background: #fffbeb; color: var(--warning); border: 1px solid #fde68a; }
.alert-info { background: var(--primary-light); color: var(--primary); border: 1px solid var(--primary-light); }
.alert-success { background: #f0fdf4; color: var(--success); border: 1px solid #bbf7d0; }

.product-info { display: flex; flex-direction: column; gap: 8px; }
.info-row { display: flex; justify-content: space-between; align-items: center; padding: 6px 0; border-bottom: 1px solid var(--gray-100); }
.info-label { color: var(--gray-500); font-size: 13px; }
.info-value { font-weight: 500; }

.stock-list { display: flex; flex-direction: column; gap: 6px; }
.stock-item { display: flex; justify-content: space-between; align-items: center; padding: 8px 12px; background: var(--gray-50); border-radius: 6px; }

.bin-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  right: auto;
  min-width: 200px;
  max-width: 300px;
  max-height: 250px;
  overflow-y: auto;
  background: #fff;
  border: 1px solid var(--gray-200, #e5e7eb);
  border-radius: 6px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  z-index: 1000;
}


.bin-drag-row.drag-over-top { border-top: 3px solid var(--primary) !important; }
.bin-drag-row.drag-over-bottom { border-bottom: 3px solid var(--primary) !important; }