/* ERP CRM - Enhanced UI/UX Design System
 * Modern, Accessible, Responsive
 * Version 2.0 - Complete Redesign
 */

/* ============================================
   CSS CUSTOM PROPERTIES (Design Tokens)
   ============================================ */
:root {
  /* Primary Colors */
  --primary: #2563eb;
  --primary-light: #3b82f6;
  --primary-dark: #1d4ed8;
  --primary-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
  
  /* Semantic Colors */
  --success: #10b981;
  --success-light: #d1fae5;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --danger: #ef4444;
  --danger-light: #fee2e2;
  --info: #06b6d4;
  --info-light: #cffafe;
  
  /* Neutral Colors */
  --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;
  
  /* Typography */
  --font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  /* Spacing */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-5: 1.25rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-10: 2.5rem;
  --spacing-12: 3rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition: 200ms ease;
  --transition-slow: 300ms ease;
  
  /* Layout */
  --sidebar-width: 260px;
  --sidebar-collapsed-width: 70px;
  --header-height: 64px;
  --content-max-width: 1400px;
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --gray-50: #111827;
  --gray-100: #1f2937;
  --gray-200: #374151;
  --gray-300: #4b5563;
  --gray-400: #6b7280;
  --gray-500: #9ca3af;
  --gray-600: #d1d5db;
  --gray-700: #e5e7eb;
  --gray-800: #f3f4f6;
  --gray-900: #f9fafb;
  
  --bg-primary: #0f0f0f;
  --bg-secondary: #1a1a1a;
  --bg-card: #1e1e1e;
  --text-primary: #f9fafb;
  --text-secondary: #d1d5db;
  --text-muted: #9ca3af;
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--gray-800);
  background: var(--gray-100);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Focus Visible for Accessibility */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* Selection */
::selection {
  background: var(--primary);
  color: white;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
  background: var(--gray-400);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--gray-500);
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--gray-900);
  margin-bottom: var(--spacing-4);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

p {
  margin-bottom: var(--spacing-4);
  color: var(--gray-600);
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

/* ============================================
   LAYOUT COMPONENTS
   ============================================ */

/* Main Container */
.app-container {
  display: flex;
  min-height: 100vh;
}

/* Main Content Area */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: var(--spacing-6);
  max-width: calc(100% - var(--sidebar-width));
  transition: margin-left var(--transition), max-width var(--transition);
}

/* ============================================
   SIDEBAR / NAVIGATION
   ============================================ */
.sidebar {
  position: fixed;
  left: 0;
  top: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--gray-900);
  color: white;
  display: flex;
  flex-direction: column;
  z-index: 1000;
  transition: width var(--transition);
  overflow-x: hidden;
}

.sidebar-header {
  padding: var(--spacing-6);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  color: white;
  font-size: var(--font-size-xl);
  font-weight: 700;
  text-decoration: none;
}

.sidebar-brand i {
  font-size: var(--font-size-2xl);
  color: var(--primary-light);
}

.sidebar-company-info {
  margin-top: var(--spacing-4);
  padding: var(--spacing-3);
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
}

.sidebar-company-info h5 {
  color: white;
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-1);
}

.sidebar-company-info small {
  color: var(--gray-400);
  font-size: var(--font-size-xs);
}

/* Navigation Menu */
.sidebar-nav {
  flex: 1;
  padding: var(--spacing-4) 0;
  overflow-y: auto;
}

.nav-section {
  margin-bottom: var(--spacing-4);
}

.nav-section-title {
  padding: var(--spacing-2) var(--spacing-6);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--gray-500);
}

.nav-item {
  list-style: none;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  padding: var(--spacing-3) var(--spacing-6);
  color: var(--gray-300);
  text-decoration: none;
  font-size: var(--font-size-sm);
  font-weight: 500;
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
  position: relative;
}

.nav-link i {
  width: 20px;
  text-align: center;
  font-size: var(--font-size-base);
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.05);
  color: white;
  text-decoration: none;
}

.nav-link.active {
  background: rgba(37, 99, 235, 0.15);
  color: var(--primary-light);
  border-left-color: var(--primary-light);
  font-weight: 600;
}

.nav-link .badge {
  margin-left: auto;
  font-size: var(--font-size-xs);
  padding: 2px 8px;
}

/* Sidebar Footer */
.sidebar-footer {
  padding: var(--spacing-4) var(--spacing-6);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.user-info {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  margin-bottom: var(--spacing-3);
}

.user-avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
  font-size: var(--font-size-sm);
}

.user-details {
  flex: 1;
}

.user-name {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: white;
}

.user-role {
  font-size: var(--font-size-xs);
  color: var(--gray-400);
}

/* ============================================
   HEADER / TOP BAR
   ============================================ */
.top-header {
  background: white;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--spacing-6);
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.header-left {
  display: flex;
  align-items: center;
  gap: var(--spacing-4);
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: var(--font-size-xl);
  color: var(--gray-600);
  cursor: pointer;
  padding: var(--spacing-2);
}

.page-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--gray-800);
  margin: 0;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: var(--font-size-sm);
  color: var(--gray-500);
}

.breadcrumb a {
  color: var(--gray-500);
}

.breadcrumb a:hover {
  color: var(--primary);
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--spacing-4);
}

.header-search {
  position: relative;
  width: 250px;
}

.header-search input {
  width: 100%;
  padding: var(--spacing-2) var(--spacing-4);
  padding-left: var(--spacing-10);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  background: var(--gray-50);
  transition: all var(--transition-fast);
}

.header-search input:focus {
  outline: none;
  border-color: var(--primary);
  background: white;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.header-search i {
  position: absolute;
  left: var(--spacing-3);
  top: 50%;
  transform: translateY(-50%);
  color: var(--gray-400);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.header-btn {
  position: relative;
  background: none;
  border: none;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gray-600);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.header-btn:hover {
  background: var(--gray-100);
  color: var(--gray-800);
}

.header-btn .notification-badge {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 8px;
  height: 8px;
  background: var(--danger);
  border-radius: var(--radius-full);
}

.theme-toggle {
  background: none;
  border: none;
  font-size: var(--font-size-lg);
  color: var(--gray-600);
  cursor: pointer;
  padding: var(--spacing-2);
  transition: color var(--transition-fast);
}

.theme-toggle:hover {
  color: var(--gray-800);
}

/* ============================================
   CARDS
   ============================================ */
.card {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
  transition: all var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

.card-header {
  padding: var(--spacing-4) var(--spacing-6);
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--gray-800);
  margin: 0;
}

.card-body {
  padding: var(--spacing-6);
}

.card-footer {
  padding: var(--spacing-4) var(--spacing-6);
  border-top: 1px solid var(--gray-200);
  background: var(--gray-50);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

/* Stat Cards */
.stat-card {
  background: white;
  border-radius: var(--radius-xl);
  padding: var(--spacing-6);
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  gap: var(--spacing-4);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
}

.stat-card.primary::before { background: var(--primary); }
.stat-card.success::before { background: var(--success); }
.stat-card.warning::before { background: var(--warning); }
.stat-card.info::before { background: var(--info); }
.stat-card.danger::before { background: var(--danger); }

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.stat-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-2xl);
}

.stat-card.primary .stat-icon {
  background: rgba(37, 99, 235, 0.1);
  color: var(--primary);
}

.stat-card.success .stat-icon {
  background: rgba(16, 185, 129, 0.1);
  color: var(--success);
}

.stat-card.warning .stat-icon {
  background: rgba(245, 158, 11, 0.1);
  color: var(--warning);
}

.stat-card.info .stat-icon {
  background: rgba(6, 182, 212, 0.1);
  color: var(--info);
}

.stat-card.danger .stat-icon {
  background: rgba(239, 68, 68, 0.1);
  color: var(--danger);
}

.stat-content {
  flex: 1;
}

.stat-value {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--gray-900);
  line-height: 1;
  margin-bottom: var(--spacing-1);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--gray-500);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.025em;
}

.stat-change {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
  font-size: var(--font-size-xs);
  margin-top: var(--spacing-2);
}

.stat-change.positive { color: var(--success); }
.stat-change.negative { color: var(--danger); }

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-4);
  font-size: var(--font-size-sm);
  font-weight: 500;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-dark);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: var(--gray-600);
  color: white;
}

.btn-secondary:hover:not(:disabled) {
  background: var(--gray-700);
  color: white;
}

.btn-success {
  background: var(--success);
  color: white;
}

.btn-success:hover:not(:disabled) {
  background: #059669;
  color: white;
}

.btn-warning {
  background: var(--warning);
  color: white;
}

.btn-warning:hover:not(:disabled) {
  background: #d97706;
  color: white;
}

.btn-danger {
  background: var(--danger);
  color: white;
}

.btn-danger:hover:not(:disabled) {
  background: #dc2626;
  color: white;
}

.btn-info {
  background: var(--info);
  color: white;
}

.btn-info:hover:not(:disabled) {
  background: #0891b2;
  color: white;
}

.btn-outline-primary {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}

.btn-outline-primary:hover:not(:disabled) {
  background: var(--primary);
  color: white;
}

.btn-outline-secondary {
  background: transparent;
  border: 2px solid var(--gray-300);
  color: var(--gray-600);
}

.btn-outline-secondary:hover:not(:disabled) {
  background: var(--gray-100);
  border-color: var(--gray-400);
  color: var(--gray-800);
}

.btn-ghost {
  background: transparent;
  color: var(--gray-600);
}

.btn-ghost:hover:not(:disabled) {
  background: var(--gray-100);
  color: var(--gray-800);
}

/* Button Sizes */
.btn-sm {
  padding: var(--spacing-1) var(--spacing-3);
  font-size: var(--font-size-xs);
}

.btn-lg {
  padding: var(--spacing-3) var(--spacing-6);
  font-size: var(--font-size-base);
}

/* Icon Buttons */
.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
}

.btn-icon.btn-sm {
  width: 32px;
  height: 32px;
}

/* Button Group */
.btn-group {
  display: inline-flex;
  gap: var(--spacing-1);
}

.btn-group .btn {
  border-radius: 0;
}

.btn-group .btn:first-child {
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.btn-group .btn:last-child {
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

/* ============================================
   FORMS
   ============================================ */
.form-group {
  margin-bottom: var(--spacing-4);
}

.form-label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: var(--spacing-2);
}

.form-label.required::after {
  content: '*';
  color: var(--danger);
  margin-left: var(--spacing-1);
}

.form-hint {
  font-size: var(--font-size-xs);
  color: var(--gray-500);
  margin-top: var(--spacing-1);
}

.form-control,
.form-select,
.form-textarea {
  width: 100%;
  padding: var(--spacing-2) var(--spacing-3);
  font-size: var(--font-size-sm);
  font-family: inherit;
  color: var(--gray-800);
  background: white;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.form-control:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-control::placeholder {
  color: var(--gray-400);
}

.form-control:disabled,
.form-select:disabled {
  background: var(--gray-100);
  cursor: not-allowed;
}

.form-control.error,
.form-select.error {
  border-color: var(--danger);
}

.form-control.success,
.form-select.success {
  border-color: var(--success);
}

/* Input with icon */
.input-group {
  position: relative;
  display: flex;
  align-items: center;
}

.input-group .form-control {
  padding-left: var(--spacing-10);
}

.input-group i {
  position: absolute;
  left: var(--spacing-3);
  color: var(--gray-400);
  pointer-events: none;
}

.input-group .input-icon-right {
  left: auto;
  right: var(--spacing-3);
}

/* Select */
.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%236b7280' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--spacing-3) center;
  padding-right: var(--spacing-10);
}

/* Checkbox & Radio */
.form-check {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  cursor: pointer;
}

.form-check input[type="checkbox"],
.form-check input[type="radio"] {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
  cursor: pointer;
}

.form-check-label {
  font-size: var(--font-size-sm);
  color: var(--gray-700);
  cursor: pointer;
}

/* Toggle Switch */
.toggle-switch {
  position: relative;
  display: inline-block;
  width: 48px;
  height: 24px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gray-300);
  border-radius: var(--radius-full);
  transition: var(--transition-fast);
}

.toggle-slider::before {
  position: absolute;
  content: '';
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background: white;
  border-radius: var(--radius-full);
  transition: var(--transition-fast);
}

.toggle-switch input:checked + .toggle-slider {
  background: var(--primary);
}

.toggle-switch input:checked + .toggle-slider::before {
  transform: translateX(24px);
}

/* ============================================
   TABLES
   ============================================ */
.table-container {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.table {
  width: 100%;
  border-collapse: collapse;
  background: white;
  font-size: var(--font-size-sm);
}

.table thead {
  background: var(--gray-50);
}

.table th {
  padding: var(--spacing-3) var(--spacing-4);
  text-align: left;
  font-weight: 600;
  color: var(--gray-700);
  font-size: var(--font-size-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 2px solid var(--gray-200);
  white-space: nowrap;
}

.table td {
  padding: var(--spacing-3) var(--spacing-4);
  border-bottom: 1px solid var(--gray-100);
  color: var(--gray-600);
  vertical-align: middle;
}

.table tbody tr {
  transition: background var(--transition-fast);
}

.table tbody tr:hover {
  background: var(--gray-50);
}

.table tbody tr:last-child td {
  border-bottom: none;
}

/* Sortable columns */
.table th.sortable {
  cursor: pointer;
  user-select: none;
}

.table th.sortable:hover {
  background: var(--gray-100);
}

.table th.sortable::after {
  content: '\f0dc';
  font-family: 'Font Awesome 6 Free';
  font-weight: 900;
  margin-left: var(--spacing-2);
  opacity: 0.3;
}

.table th.sortable.asc::after {
  content: '\f0de';
  opacity: 1;
}

.table th.sortable.desc::after {
  content: '\f0dd';
  opacity: 1;
}

/* Table Actions */
.table-actions {
  display: flex;
  gap: var(--spacing-1);
}

.table-actions .btn {
  width: 32px;
  height: 32px;
  padding: 0;
}

/* ============================================
   BADGES & TAGS
   ============================================ */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-1);
  padding: var(--spacing-1) var(--spacing-2);
  font-size: var(--font-size-xs);
  font-weight: 500;
  border-radius: var(--radius-full);
  white-space: nowrap;
}

.badge-primary {
  background: rgba(37, 99, 235, 0.1);
  color: var(--primary);
}

.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-info {
  background: var(--info-light);
  color: var(--info);
}

.badge-secondary {
  background: var(--gray-100);
  color: var(--gray-600);
}

/* ============================================
   MODALS
   ============================================ */
.erp-modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  animation: fadeIn var(--transition-fast);
}

.erp-modal-backdrop.show {
  display: flex;
}

.erp-modal {
  background: white;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow: hidden;
  animation: slideUp var(--transition);
  margin: var(--spacing-4);
}

.erp-modal.erp-modal-lg {
  max-width: 800px;
}

.erp-modal.erp-modal-sm {
  max-width: 350px;
}

.modal-header {
  padding: var(--spacing-4) var(--spacing-6);
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--gray-800);
  margin: 0;
}

.modal-close {
  background: none;
  border: none;
  font-size: var(--font-size-xl);
  color: var(--gray-400);
  cursor: pointer;
  padding: var(--spacing-1);
  transition: color var(--transition-fast);
}

.modal-close:hover {
  color: var(--gray-600);
}

.modal-body {
  padding: var(--spacing-6);
  overflow-y: auto;
  max-height: calc(90vh - 140px);
}

.modal-footer {
  padding: var(--spacing-4) var(--spacing-6);
  border-top: 1px solid var(--gray-200);
  display: flex;
  justify-content: flex-end;
  gap: var(--spacing-2);
  background: var(--gray-50);
}

/* ============================================
   TOAST NOTIFICATIONS
   ============================================ */
.toast-container {
  position: fixed;
  top: var(--spacing-6);
  right: var(--spacing-6);
  z-index: 3000;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.toast {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-4);
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  min-width: 300px;
  max-width: 400px;
  animation: slideInRight var(--transition);
  border-left: 4px solid var(--gray-400);
}

.toast.success { border-left-color: var(--success); }
.toast.warning { border-left-color: var(--warning); }
.toast.error { border-left-color: var(--danger); }
.toast.info { border-left-color: var(--info); }

.toast-icon {
  font-size: var(--font-size-xl);
}

.toast.success .toast-icon { color: var(--success); }
.toast.warning .toast-icon { color: var(--warning); }
.toast.error .toast-icon { color: var(--danger); }
.toast.info .toast-icon { color: var(--info); }

.toast-content {
  flex: 1;
}

.toast-title {
  font-weight: 600;
  color: var(--gray-800);
  font-size: var(--font-size-sm);
}

.toast-message {
  font-size: var(--font-size-xs);
  color: var(--gray-500);
  margin-top: var(--spacing-1);
}

.toast-close {
  background: none;
  border: none;
  color: var(--gray-400);
  cursor: pointer;
  padding: var(--spacing-1);
}

.toast-close:hover {
  color: var(--gray-600);
}

/* ============================================
   LOADING STATES
   ============================================ */
.loading-spinner {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--gray-200);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.spinner-sm {
  width: 20px;
  height: 20px;
  border-width: 2px;
}

.spinner-lg {
  width: 60px;
  height: 60px;
  border-width: 4px;
}

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

/* Skeleton Loading */
.skeleton {
  background: linear-gradient(90deg, var(--gray-200) 25%, var(--gray-100) 50%, var(--gray-200) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius);
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ============================================
   TABS
   ============================================ */
.tabs {
  border-bottom: 1px solid var(--gray-200);
  display: flex;
  gap: var(--spacing-1);
}

.tab {
  padding: var(--spacing-3) var(--spacing-4);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--gray-500);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-bottom: -1px;
}

.tab:hover {
  color: var(--gray-700);
}

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

.tab-content {
  padding: var(--spacing-6) 0;
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: block;
  animation: fadeIn var(--transition-fast);
}

/* ============================================
   PAGINATION
   ============================================ */
.pagination {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
}

.pagination-item {
  min-width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--gray-600);
  background: white;
  border: 1px solid var(--gray-200);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.pagination-item:hover {
  background: var(--gray-50);
  border-color: var(--gray-300);
}

.pagination-item.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

.pagination-item:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ============================================
   EMPTY STATES
   ============================================ */
.empty-state {
  text-align: center;
  padding: var(--spacing-12) var(--spacing-6);
}

.empty-state-icon {
  font-size: 4rem;
  color: var(--gray-300);
  margin-bottom: var(--spacing-4);
}

.empty-state-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: var(--spacing-2);
}

.empty-state-description {
  color: var(--gray-500);
  margin-bottom: var(--spacing-6);
}

/* ============================================
   INVOICE SPECIFIC STYLES
   ============================================ */
.invoice-container {
  background: white;
  max-width: 210mm;
  margin: 0 auto;
  padding: 15mm;
  box-shadow: var(--shadow);
  border: 1px solid var(--gray-200);
}

.invoice-header {
  border-bottom: 2px solid var(--gray-800);
  padding-bottom: var(--spacing-4);
  margin-bottom: var(--spacing-6);
}

.invoice-table th {
  background: var(--gray-100) !important;
  font-size: var(--font-size-xs);
  text-transform: uppercase;
}

.invoice-controls {
  background: var(--gray-50);
  padding: var(--spacing-4);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-4);
  display: flex;
  gap: var(--spacing-2);
  flex-wrap: wrap;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 1200px) {
  .main-content {
    padding: var(--spacing-4);
  }
}

@media (max-width: 992px) {
  .sidebar {
    transform: translateX(-100%);
    transition: transform var(--transition);
  }

  .sidebar.show {
    transform: translateX(0);
  }

  .main-content {
    margin-left: 0;
    max-width: 100%;
  }

  .mobile-menu-toggle {
    display: block;
  }

  .header-search {
    display: none;
  }

  .stat-card {
    padding: var(--spacing-4);
  }

  .stat-icon {
    width: 48px;
    height: 48px;
    font-size: var(--font-size-xl);
  }

  .stat-value {
    font-size: var(--font-size-xl);
  }
}

@media (max-width: 768px) {
  .top-header {
    padding: 0 var(--spacing-4);
  }

  .page-title {
    font-size: var(--font-size-lg);
  }

  .card-body {
    padding: var(--spacing-4);
  }

  .table th,
  .table td {
    padding: var(--spacing-2) var(--spacing-3);
  }

  .modal {
    margin: var(--spacing-2);
    max-height: 95vh;
  }

  .modal-body {
    padding: var(--spacing-4);
  }

  .invoice-container {
    padding: 10mm;
    font-size: var(--font-size-sm);
  }
}

@media (max-width: 576px) {
  .stat-cards-grid {
    grid-template-columns: 1fr;
  }

  .btn-group-responsive {
    flex-direction: column;
    width: 100%;
  }

  .btn-group-responsive .btn {
    width: 100%;
  }

  .invoice-controls {
    flex-direction: column;
  }

  .invoice-controls .btn {
    width: 100%;
  }
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(100%);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* Animation Classes */
.animate-fade-in {
  animation: fadeIn var(--transition);
}

.animate-fade-in-up {
  animation: fadeInUp var(--transition);
}

.animate-slide-up {
  animation: slideUp var(--transition);
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-primary { color: var(--primary) !important; }
.text-success { color: var(--success) !important; }
.text-warning { color: var(--warning) !important; }
.text-danger { color: var(--danger) !important; }
.text-info { color: var(--info) !important; }
.text-muted { color: var(--gray-500) !important; }
.text-dark { color: var(--gray-800) !important; }
.text-white { color: white !important; }

.text-center { text-align: center !important; }
.text-right { text-align: right !important; }
.text-left { text-align: left !important; }

.font-weight-normal { font-weight: 400 !important; }
.font-weight-medium { font-weight: 500 !important; }
.font-weight-semibold { font-weight: 600 !important; }
.font-weight-bold { font-weight: 700 !important; }

.bg-primary { background-color: var(--primary) !important; }
.bg-success { background-color: var(--success) !important; }
.bg-warning { background-color: var(--warning) !important; }
.bg-danger { background-color: var(--danger) !important; }
.bg-info { background-color: var(--info) !important; }
.bg-light { background-color: var(--gray-100) !important; }
.bg-white { background-color: white !important; }

.d-none { display: none !important; }
.d-block { display: block !important; }
.d-flex { display: flex !important; }
.d-grid { display: grid !important; }
.d-inline { display: inline !important; }
.d-inline-block { display: inline-block !important; }

.flex-column { flex-direction: column !important; }
.flex-wrap { flex-wrap: wrap !important; }
.align-items-center { align-items: center !important; }
.justify-content-center { justify-content: center !important; }
.justify-content-between { justify-content: space-between !important; }
.gap-1 { gap: var(--spacing-1) !important; }
.gap-2 { gap: var(--spacing-2) !important; }
.gap-3 { gap: var(--spacing-3) !important; }
.gap-4 { gap: var(--spacing-4) !important; }

.m-0 { margin: 0 !important; }
.mt-1 { margin-top: var(--spacing-1) !important; }
.mt-2 { margin-top: var(--spacing-2) !important; }
.mt-3 { margin-top: var(--spacing-3) !important; }
.mt-4 { margin-top: var(--spacing-4) !important; }
.mb-1 { margin-bottom: var(--spacing-1) !important; }
.mb-2 { margin-bottom: var(--spacing-2) !important; }
.mb-3 { margin-bottom: var(--spacing-3) !important; }
.mb-4 { margin-bottom: var(--spacing-4) !important; }

.p-0 { padding: 0 !important; }
.p-1 { padding: var(--spacing-1) !important; }
.p-2 { padding: var(--spacing-2) !important; }
.p-3 { padding: var(--spacing-3) !important; }
.p-4 { padding: var(--spacing-4) !important; }

.w-100 { width: 100% !important; }
.h-100 { height: 100% !important; }

.rounded { border-radius: var(--radius) !important; }
.rounded-lg { border-radius: var(--radius-lg) !important; }
.rounded-full { border-radius: var(--radius-full) !important; }

.shadow { box-shadow: var(--shadow) !important; }
.shadow-md { box-shadow: var(--shadow-md) !important; }
.shadow-lg { box-shadow: var(--shadow-lg) !important; }

.overflow-hidden { overflow: hidden !important; }
.overflow-auto { overflow: auto !important; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ============================================
   QR CODE CORNER DISPLAY
   ============================================ */
.qr-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 10000;
  background: white;
  padding: 12px;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  border: 2px solid var(--primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-2);
  min-width: 140px;
}

#qrCanvas {
  width: 100px;
  height: 100px;
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-300);
}

@media print {
  .qr-container {
    display: none !important;
  }
}

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
  .sidebar,
  .top-header,
  .btn,
  .no-print {
    display: none !important;
  }


  .main-content {
    margin: 0;
    padding: 0;
    max-width: 100%;
  }

  .invoice-container {
    box-shadow: none;
    border: none;
    max-width: 100%;
    padding: 0;
  }

  body {
    background: white;
  }

  @page {
    margin: 10mm;
    size: A4;
  }
}

/* ============================================
   ACCESSIBILITY
   ============================================ */
/* Skip to content link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary);
  color: white;
  padding: var(--spacing-2) var(--spacing-4);
  z-index: 9999;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 0;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --primary: #0040c1;
    --gray-400: #666;
    --gray-500: #555;
    --gray-600: #444;
  }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}