/* ============================================
   Admin Panel Styles - Centralized CSS
   Production-Ready UI/UX
   ============================================ */

/* ============================================
   Variables & Base Styles
   ============================================ */
:root {
  --primary-color: #667eea;
  --primary-dark: #764ba2;
  --secondary-color: #6c757d;
  --success-color: #28a745;
  --danger-color: #dc3545;
  --warning-color: #ffc107;
  --info-color: #17a2b8;
  
  --text-primary: #333;
  --text-secondary: #666;
  --text-muted: #999;
  
  --bg-primary: #ffffff;
  --bg-secondary: #f5f7fa;
  --bg-light: #f8f9fa;
  
  --border-color: #e0e0e0;
  --border-radius: 8px;
  --border-radius-lg: 10px;
  
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
  --shadow-md: 0 2px 10px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.1);
  
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  
  --transition: all 0.3s ease;
  
  --max-width: 1400px;
  --max-width-form: 600px;
  --max-width-card: 1000px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: var(--bg-secondary);
  color: var(--text-primary);
  line-height: 1.6;
}

/* ============================================
   Admin Header
   ============================================ */
.admin-header {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
  color: white;
  padding: 1rem 2rem;
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.admin-header-content {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.admin-header h1 {
  font-size: 1.5rem;
  font-weight: bold;
}

.admin-nav {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  flex-wrap: wrap;
}

.admin-nav a {
  color: white;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius);
  transition: var(--transition);
  font-size: 0.9rem;
}

.admin-nav a:hover,
.admin-nav a:focus {
  background: rgba(255,255,255,0.2);
  outline: 2px solid rgba(255,255,255,0.3);
  outline-offset: 2px;
}

.admin-nav span {
  font-size: 0.9rem;
  opacity: 0.9;
}

/* ============================================
   Container & Layout
   ============================================ */
.admin-container {
  max-width: var(--max-width);
  margin: 2rem auto;
  padding: 0 2rem;
}

.page-container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.page-container-form {
  max-width: var(--max-width-form);
}

.page-container-card {
  max-width: var(--max-width-card);
}

/* ============================================
   Flash Messages & Alerts
   ============================================ */
.flash-messages {
  margin-bottom: 1.5rem;
  animation: slideDown 0.3s ease;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.alert {
  padding: 1rem 1.25rem;
  border-radius: var(--border-radius);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  border-left: 4px solid;
  animation: slideDown 0.3s ease;
}

.alert::before {
  font-size: 1.25rem;
  line-height: 1;
}

.alert.notice,
.alert.success {
  background: #d4edda;
  color: #155724;
  border-color: #28a745;
}

.alert.notice::before,
.alert.success::before {
  content: "✅";
}

.alert.alert,
.alert.error,
.alert-danger {
  background: #f8d7da;
  color: #721c24;
  border-color: var(--danger-color);
}

.alert.alert::before,
.alert.error::before,
.alert-danger::before {
  content: "❌";
}

.alert.warning {
  background: #fff3cd;
  color: #856404;
  border-color: var(--warning-color);
}

.alert.warning::before {
  content: "⚠️";
}

.alert.info {
  background: #d1ecf1;
  color: #0c5460;
  border-color: var(--info-color);
}

.alert.info::before {
  content: "ℹ️";
}

/* ============================================
   Buttons - Unified System
   ============================================ */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--border-radius);
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  text-decoration: none;
  text-align: center;
  transition: var(--transition);
  position: relative;
  line-height: 1.5;
  user-select: none;
}

.btn:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

.btn:disabled,
.btn.loading {
  opacity: 0.6;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

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

.btn-secondary:hover:not(:disabled) {
  background: #5a6268;
  transform: translateY(-1px);
}

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

.btn-danger:hover:not(:disabled) {
  background: #c82333;
  transform: translateY(-1px);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
}

.btn-link {
  background: none;
  color: var(--primary-color);
  padding: 0.5rem;
  box-shadow: none;
}

.btn-link:hover {
  text-decoration: underline;
  transform: none;
}

/* Loading State */
.btn.loading::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  margin: auto;
  border: 2px solid transparent;
  border-top-color: currentColor;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
}

@keyframes spin {
  0% { transform: translateY(-50%) rotate(0deg); }
  100% { transform: translateY(-50%) rotate(360deg); }
}

/* ============================================
   Forms
   ============================================ */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.9rem;
}

.form-label.required::after {
  content: " *";
  color: var(--danger-color);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  font-size: 1rem;
  transition: var(--transition);
  background: var(--bg-primary);
  font-family: inherit;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-input:invalid:not(:placeholder-shown),
.form-input.error {
  border-color: var(--danger-color);
}

.form-input:valid:not(:placeholder-shown) {
  border-color: var(--success-color);
}

.form-textarea {
  min-height: 100px;
  resize: vertical;
}

.form-help {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.form-error {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.85rem;
  color: var(--danger-color);
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.form-error::before {
  content: "⚠️";
  font-size: 0.75rem;
}

.form-actions {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

/* ============================================
   Cards & Containers
   ============================================ */
.card {
  background: var(--bg-primary);
  padding: 1.5rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  margin-bottom: var(--spacing-lg);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--bg-secondary);
}

.card-header h2,
.card-header h3 {
  margin: 0;
  color: var(--text-primary);
}

.card-body {
  padding: 0;
}

.card-body > *:first-child {
  margin-top: 0;
}

.card-body > *:last-child {
  margin-bottom: 0;
}

.info-card {
  background: var(--bg-primary);
  padding: 1.5rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
}

.info-card h3 {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.info-card p {
  margin: 0.625rem 0;
  color: var(--text-secondary);
}

/* ============================================
   Tables
   ============================================ */
.data-table {
  width: 100%;
  background: var(--bg-primary);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  border-collapse: collapse;
}

.data-table thead {
  background: var(--bg-light);
}

.data-table th {
  padding: 1rem;
  text-align: left;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.data-table td {
  padding: 1rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
}

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

.data-table tbody tr:hover {
  background: var(--bg-light);
}

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

/* ============================================
   Grids
   ============================================ */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
}

/* ============================================
   Empty States
   ============================================ */
.empty-state {
  text-align: center;
  padding: 3rem 2rem;
  color: var(--text-muted);
}

.empty-state-icon {
  font-size: 4rem;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-state h3 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.empty-state p {
  margin-bottom: 1.5rem;
  color: var(--text-muted);
}

/* ============================================
   Badges & Tags
   ============================================ */
.badge {
  display: inline-block;
  padding: 0.375rem 0.75rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  line-height: 1;
}

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

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

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

.badge-secondary {
  background: var(--secondary-color);
  color: white;
}

.tag {
  display: inline-block;
  padding: 0.375rem 0.75rem;
  background: var(--bg-light);
  border-radius: 15px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin: 0.25rem;
}

/* ============================================
   Search & Filters
   ============================================ */
.search-bar {
  margin-bottom: var(--spacing-lg);
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.search-bar input[type="text"],
.search-bar input[type="search"] {
  flex: 1;
  min-width: 200px;
  padding: 0.75rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  font-size: 1rem;
}

.search-bar input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-loading {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid var(--border-color);
  border-top-color: var(--primary-color);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-left: 0.5rem;
  vertical-align: middle;
}

/* ============================================
   Pagination
   ============================================ */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-lg);
  flex-wrap: wrap;
}

.pagination-info {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin: 0 var(--spacing-md);
}

.pagination a,
.pagination span {
  padding: 0.5rem 0.75rem;
  border-radius: var(--border-radius);
  text-decoration: none;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.pagination a:hover {
  background: var(--bg-light);
  border-color: var(--primary-color);
}

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

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

/* ============================================
   Header Actions
   ============================================ */
.header-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.header-actions h1 {
  margin: 0;
  color: var(--text-primary);
  font-size: 2rem;
}

.header-actions .actions {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
  .admin-header {
    padding: 1rem;
  }
  
  .admin-header-content {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .admin-nav {
    width: 100%;
    justify-content: flex-start;
  }
  
  .admin-container {
    padding: 0 1rem;
    margin: 1rem auto;
  }
  
  .header-actions {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .header-actions h1 {
    font-size: 1.5rem;
  }
  
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .data-table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  .data-table thead {
    display: none;
  }
  
  .data-table tbody,
  .data-table tr,
  .data-table td {
    display: block;
    width: 100%;
  }
  
  .data-table tr {
    margin-bottom: var(--spacing-md);
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    padding: var(--spacing-md);
  }
  
  .data-table td {
    border: none;
    padding: 0.5rem 0;
    text-align: left;
  }
  
  .data-table td::before {
    content: attr(data-label) ": ";
    font-weight: 600;
    color: var(--text-primary);
    display: inline-block;
    min-width: 100px;
  }
  
  .form-actions {
    flex-direction: column;
  }
  
  .form-actions .btn {
    width: 100%;
  }
  
  .search-bar {
    flex-direction: column;
  }
  
  .search-bar input {
    width: 100%;
  }
  
  .pagination {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .admin-header h1 {
    font-size: 1.25rem;
  }
  
  .header-actions h1 {
    font-size: 1.25rem;
  }
  
  .card {
    padding: 1rem;
  }
  
  .btn {
    padding: 0.625rem 1.25rem;
    font-size: 0.9rem;
  }
}

/* ============================================
   Accessibility
   ============================================ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary-color);
  color: white;
  padding: 0.5rem 1rem;
  text-decoration: none;
  z-index: 10000;
}

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

/* Focus indicators */
*:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

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

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

.fade-in {
  animation: fadeIn 0.3s ease;
}

.slide-up {
  animation: slideUp 0.3s ease;
}

/* ============================================
   Shop-Specific Styles
   ============================================ */
.shop-card {
  transition: var(--transition);
}

.shop-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.shop-info p {
  margin: 0.5rem 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.shop-info strong {
  color: var(--text-primary);
  font-weight: 600;
}

.shop-actions {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.shop-code-badge {
  font-family: 'Courier New', monospace;
  letter-spacing: 1px;
}

.items-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin: 1rem 0;
}

.items-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-md);
}

.item-card {
  background: var(--bg-light);
  padding: 1rem;
  border-radius: var(--border-radius);
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition);
}

.item-card:hover {
  background: #e9ecef;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.item-name {
  font-weight: 500;
  color: var(--text-primary);
}

.item-actions {
  display: flex;
  gap: var(--spacing-xs);
}

/* ============================================
   Message Styles
   ============================================ */
.messages-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.message {
  padding: 1rem;
  border-radius: var(--border-radius);
  border-left: 4px solid;
  transition: var(--transition);
}

.message:hover {
  transform: translateX(4px);
}

.message-incoming {
  background: #e3f2fd;
  border-color: #2196f3;
}

.message-outgoing {
  background: #e8f5e9;
  border-color: #4caf50;
}

.message-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.message-text {
  color: var(--text-primary);
  line-height: 1.6;
  word-wrap: break-word;
}

.message-type {
  margin-top: 0.5rem;
  padding-top: 0.5rem;
  border-top: 1px solid rgba(0,0,0,0.1);
}

.message-type small {
  color: var(--text-muted);
  font-size: 0.75rem;
}

.message-text-box {
  background: var(--bg-light);
  padding: 1.25rem;
  border-radius: var(--border-radius);
  margin-top: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  white-space: pre-wrap;
  word-wrap: break-word;
}

/* ============================================
   Filters & Selects
   ============================================ */
.filters {
  margin-bottom: var(--spacing-lg);
}

.form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  font-size: 1rem;
  background: var(--bg-primary);
  cursor: pointer;
  transition: var(--transition);
}

.form-select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* ============================================
   Table Responsive Wrapper
   ============================================ */
.table-responsive {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

@media (max-width: 768px) {
  .table-responsive {
    margin: 0 -1rem;
    padding: 0 1rem;
  }
}

/* ============================================
   Dashboard Stats
   ============================================ */
.stat-card {
  text-align: center;
  transition: var(--transition);
}

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

.stat-card h3 {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 0.625rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: bold;
  color: var(--primary-color);
  margin: 0.625rem 0;
  line-height: 1.2;
}

.stat-card small {
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ============================================
   Login Page
   ============================================ */
.login-page {
  min-height: calc(100vh - 200px);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 2rem 1rem;
}

.login-container {
  max-width: 450px;
  width: 100%;
}

.login-header {
  text-align: center;
  margin-bottom: 2rem;
}

.login-header h1 {
  font-size: 2rem;
  color: var(--text-primary);
  margin-bottom: 0.625rem;
  font-weight: 700;
}

.login-header p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.btn-login {
  width: 100%;
}

.login-footer {
  text-align: center;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-color);
  margin-top: 1.5rem;
}

.login-footer p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin: 0;
}

.login-footer code {
  background: var(--bg-light);
  padding: 0.125rem 0.375rem;
  border-radius: 4px;
  font-size: 0.85em;
  color: var(--primary-color);
  font-weight: 600;
}

/* ============================================
   Utility Classes
   ============================================ */
.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mt-4 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.mb-4 { margin-bottom: var(--spacing-xl); }

.d-flex {
  display: flex;
}

.gap-1 { gap: var(--spacing-sm); }
.gap-2 { gap: var(--spacing-md); }
.gap-3 { gap: var(--spacing-lg); }

.flex-wrap {
  flex-wrap: wrap;
}

.justify-between {
  justify-content: space-between;
}

.align-center {
  align-items: center;
}