/* ============================================
   NEXX BURGER UNIFIED DESIGN SYSTEM
   Apple-Inspired Design Language
   ============================================ */

/* ============================================
   DESIGN TOKENS - Core Variables
   ============================================ */

:root {
  /* === COLOR PALETTE === */
  /* Brand Colors */
  --nb-brand-primary: #d32f2f;
  --nb-brand-secondary: #b71c1c;
  --nb-brand-dark: #8b0000;
  --nb-brand-light: #f44336;
  --nb-brand-lighter: #ffebee;
  --nb-brand-shadow: rgba(211, 47, 47, 0.3);
  --nb-brand-shadow-hover: rgba(211, 47, 47, 0.4);

  /* Neutral Colors */
  --nb-white: #ffffff;
  --nb-gray-50: #fafafa;
  --nb-gray-100: #f5f6fa;
  --nb-gray-200: #e8e8e8;
  --nb-gray-300: #d0d0d0;
  --nb-gray-400: #a0a0a0;
  --nb-gray-500: #707070;
  --nb-gray-600: #505050;
  --nb-gray-700: #333333;
  --nb-gray-800: #1a1a1a;
  --nb-gray-900: #0a0a0a;

  /* Semantic Colors */
  --nb-success: #4caf50;
  --nb-success-light: #e8f5e9;
  --nb-success-dark: #2e7d32;
  --nb-warning: #ff9800;
  --nb-warning-light: #fff3e0;
  --nb-warning-dark: #e65100;
  --nb-error: #f44336;
  --nb-error-light: #ffebee;
  --nb-error-dark: #c62828;
  --nb-info: #2196f3;
  --nb-info-light: #e3f2fd;
  --nb-info-dark: #1565c0;

  /* === SPACING SCALE (4px base) === */
  --nb-space-1: 4px;
  --nb-space-2: 8px;
  --nb-space-3: 12px;
  --nb-space-4: 16px;
  --nb-space-5: 20px;
  --nb-space-6: 24px;
  --nb-space-8: 32px;
  --nb-space-10: 40px;
  --nb-space-12: 48px;
  --nb-space-16: 64px;

  /* === BORDER RADIUS === */
  --nb-radius-sm: 8px;
  --nb-radius-md: 12px;
  --nb-radius-lg: 16px;
  --nb-radius-xl: 20px;
  --nb-radius-full: 9999px;

  /* === SHADOWS (Apple-inspired depth system) === */
  /* Level 1: Subtle - Cards on page */
  --nb-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  /* Level 2: Medium - Elevated cards, dropdowns */
  --nb-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1), 0 2px 4px rgba(0, 0, 0, 0.06);
  /* Level 3: Strong - Modals, popovers */
  --nb-shadow-lg: 0 12px 28px rgba(0, 0, 0, 0.12), 0 8px 16px rgba(0, 0, 0, 0.08);
  /* Level 4: Prominent - Elevated modals */
  --nb-shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.15), 0 12px 24px rgba(0, 0, 0, 0.1);
  /* Brand shadow for buttons */
  --nb-shadow-brand: 0 4px 12px rgba(211, 47, 47, 0.25);
  --nb-shadow-brand-hover: 0 6px 20px rgba(211, 47, 47, 0.35);

  /* === TRANSITIONS === */
  --nb-transition-fast: 150ms ease;
  --nb-transition-normal: 250ms ease;
  --nb-transition-slow: 350ms ease;
  --nb-transition-spring: 300ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* === TYPOGRAPHY === */
  --nb-font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --nb-font-size-xs: 12px;
  --nb-font-size-sm: 13px;
  --nb-font-size-base: 15px;
  --nb-font-size-md: 16px;
  --nb-font-size-lg: 18px;
  --nb-font-size-xl: 20px;
  --nb-font-size-2xl: 24px;
  --nb-font-size-3xl: 28px;
  --nb-font-size-4xl: 32px;
  --nb-font-weight-normal: 400;
  --nb-font-weight-medium: 500;
  --nb-font-weight-semibold: 600;
  --nb-font-weight-bold: 700;
  --nb-line-height-tight: 1.25;
  --nb-line-height-normal: 1.5;
  --nb-line-height-relaxed: 1.75;

  /* === Z-INDEX SCALE === */
  --nb-z-dropdown: 100;
  --nb-z-sticky: 200;
  --nb-z-modal-backdrop: 900;
  --nb-z-modal: 1000;
  --nb-z-toast: 1100;
  --nb-z-tooltip: 1200;
}

/* ============================================
   BASE STYLES
   ============================================ */

.nb-base {
  font-family: var(--nb-font-family);
  font-size: var(--nb-font-size-base);
  line-height: var(--nb-line-height-normal);
  color: var(--nb-gray-700);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   BUTTON SYSTEM
   ============================================ */

.nb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--nb-space-2);
  padding: var(--nb-space-3) var(--nb-space-5);
  min-height: 44px;
  font-family: var(--nb-font-family);
  font-size: var(--nb-font-size-sm);
  font-weight: var(--nb-font-weight-semibold);
  line-height: 1;
  text-decoration: none;
  border: none;
  border-radius: var(--nb-radius-md);
  cursor: pointer;
  transition: all var(--nb-transition-normal);
  white-space: nowrap;
}

.nb-btn:focus-visible {
  outline: 3px solid var(--nb-brand-primary);
  outline-offset: 2px;
}

.nb-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

/* Primary Button (Brand Red) */
.nb-btn-primary {
  background: var(--nb-brand-primary);
  color: var(--nb-white);
  box-shadow: var(--nb-shadow-brand);
}

.nb-btn-primary:hover:not(:disabled) {
  background: var(--nb-brand-secondary);
  box-shadow: var(--nb-shadow-brand-hover);
  transform: translateY(-1px);
}

.nb-btn-primary:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: var(--nb-shadow-sm);
}

/* Secondary Button (Glass effect) */
.nb-btn-secondary {
  background: rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  color: var(--nb-white);
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: var(--nb-shadow-sm);
}

.nb-btn-secondary:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.3);
  border-color: rgba(255, 255, 255, 0.4);
  transform: translateY(-1px);
  box-shadow: var(--nb-shadow-md);
}

/* Tertiary Button (Ghost) */
.nb-btn-tertiary {
  background: transparent;
  color: var(--nb-brand-primary);
  border: 2px solid var(--nb-brand-primary);
}

.nb-btn-tertiary:hover:not(:disabled) {
  background: var(--nb-brand-lighter);
  transform: translateY(-1px);
}

/* Ghost Button (Minimal) */
.nb-btn-ghost {
  background: transparent;
  color: var(--nb-gray-600);
}

.nb-btn-ghost:hover:not(:disabled) {
  background: var(--nb-gray-100);
  color: var(--nb-gray-700);
}

/* Success Button */
.nb-btn-success {
  background: var(--nb-success);
  color: var(--nb-white);
  box-shadow: 0 4px 12px rgba(76, 175, 80, 0.3);
}

.nb-btn-success:hover:not(:disabled) {
  background: var(--nb-success-dark);
  box-shadow: 0 6px 20px rgba(76, 175, 80, 0.4);
  transform: translateY(-1px);
}

/* Warning Button */
.nb-btn-warning {
  background: var(--nb-warning);
  color: var(--nb-white);
  box-shadow: 0 4px 12px rgba(255, 152, 0, 0.3);
}

.nb-btn-warning:hover:not(:disabled) {
  background: var(--nb-warning-dark);
  box-shadow: 0 6px 20px rgba(255, 152, 0, 0.4);
  transform: translateY(-1px);
}

/* Danger Button */
.nb-btn-danger {
  background: var(--nb-error);
  color: var(--nb-white);
  box-shadow: 0 4px 12px rgba(244, 67, 54, 0.3);
}

.nb-btn-danger:hover:not(:disabled) {
  background: var(--nb-error-dark);
  box-shadow: 0 6px 20px rgba(244, 67, 54, 0.4);
  transform: translateY(-1px);
}

/* Button Sizes */
.nb-btn-sm {
  padding: var(--nb-space-2) var(--nb-space-4);
  font-size: var(--nb-font-size-xs);
  min-height: 44px;
  border-radius: var(--nb-radius-sm);
}

.nb-btn-lg {
  padding: var(--nb-space-4) var(--nb-space-8);
  font-size: var(--nb-font-size-md);
  min-height: 52px;
  border-radius: var(--nb-radius-lg);
}

.nb-btn-full {
  width: 100%;
}

/* Icon Button */
.nb-btn-icon {
  padding: var(--nb-space-3);
  min-width: 44px;
}

/* ============================================
   FORM INPUTS
   ============================================ */

.nb-input,
.nb-select,
.nb-textarea {
  width: 100%;
  padding: var(--nb-space-3) var(--nb-space-4);
  min-height: 44px;
  font-family: var(--nb-font-family);
  font-size: var(--nb-font-size-md);
  color: var(--nb-gray-700);
  background: var(--nb-white);
  border: 2px solid var(--nb-gray-200);
  border-radius: var(--nb-radius-md);
  transition: all var(--nb-transition-normal);
}

.nb-input:hover:not(:disabled),
.nb-select:hover:not(:disabled),
.nb-textarea:hover:not(:disabled) {
  border-color: var(--nb-gray-300);
}

.nb-input:focus,
.nb-select:focus,
.nb-textarea:focus {
  outline: none;
  border-color: var(--nb-brand-primary);
  box-shadow: 0 0 0 3px rgba(211, 47, 47, 0.15);
}

.nb-input:disabled,
.nb-select:disabled,
.nb-textarea:disabled {
  background: var(--nb-gray-100);
  cursor: not-allowed;
  opacity: 0.7;
}

.nb-input::placeholder,
.nb-textarea::placeholder {
  color: var(--nb-gray-400);
}

/* Input with error */
.nb-input-error {
  border-color: var(--nb-error);
}

.nb-input-error:focus {
  box-shadow: 0 0 0 3px rgba(244, 67, 54, 0.15);
}

/* Input with success */
.nb-input-success {
  border-color: var(--nb-success);
}

.nb-input-success:focus {
  box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.15);
}

/* Form Labels */
.nb-label {
  display: block;
  margin-bottom: var(--nb-space-2);
  font-size: var(--nb-font-size-sm);
  font-weight: var(--nb-font-weight-semibold);
  color: var(--nb-gray-700);
}

/* Form Group */
.nb-form-group {
  margin-bottom: var(--nb-space-5);
}

/* Error Message */
.nb-error-text {
  display: block;
  margin-top: var(--nb-space-2);
  font-size: var(--nb-font-size-xs);
  color: var(--nb-error);
}

/* ============================================
   CARDS
   ============================================ */

.nb-card {
  background: var(--nb-white);
  border-radius: var(--nb-radius-lg);
  box-shadow: var(--nb-shadow-sm);
  overflow: hidden;
  transition: all var(--nb-transition-normal);
}

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

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

.nb-card-header {
  padding: var(--nb-space-5) var(--nb-space-6);
  border-bottom: 1px solid var(--nb-gray-200);
}

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

.nb-card-footer {
  padding: var(--nb-space-4) var(--nb-space-6);
  border-top: 1px solid var(--nb-gray-200);
  background: var(--nb-gray-50);
}

/* ============================================
   NAVIGATION TABS
   ============================================ */

.nb-nav-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--nb-space-2);
  padding: var(--nb-space-2);
}

.nb-nav-tab {
  padding: var(--nb-space-3) var(--nb-space-5);
  font-size: var(--nb-font-size-sm);
  font-weight: var(--nb-font-weight-medium);
  color: rgba(255, 255, 255, 0.85);
  background: transparent;
  border: none;
  border-radius: var(--nb-radius-sm);
  cursor: pointer;
  text-decoration: none;
  transition: all var(--nb-transition-normal);
  white-space: nowrap;
}

.nb-nav-tab:hover {
  background: rgba(255, 255, 255, 0.15);
  color: var(--nb-white);
}

.nb-nav-tab-active,
.nb-nav-tab.active {
  background: var(--nb-brand-secondary);
  color: var(--nb-white);
}

/* ============================================
   HEADER
   ============================================ */

.nb-header {
  background: var(--nb-brand-primary);
  color: var(--nb-white);
  box-shadow: var(--nb-shadow-md);
}

.nb-header-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--nb-space-4) var(--nb-space-6);
}

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

.nb-header-logo {
  height: 45px;
  width: auto;
  border-radius: var(--nb-radius-md);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.nb-header-title {
  font-size: var(--nb-font-size-2xl);
  font-weight: var(--nb-font-weight-semibold);
  margin: 0;
}

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

.nb-header-user {
  font-size: var(--nb-font-size-sm);
  opacity: 0.9;
}

.nb-header-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--nb-space-2);
  padding: 0 var(--nb-space-6) var(--nb-space-4);
  justify-content: center;
}

/* Clean text-style navigation links (Dashboard style) */
.header-nav .btn,
.header-nav .btn-primary,
.header-nav .btn-nav,
.nb-header-nav .btn,
.nb-header-nav .nb-btn {
  background: transparent !important;
  border: none !important;
  box-shadow: none !important;
  backdrop-filter: none !important;
  -webkit-backdrop-filter: none !important;
  color: var(--nb-white);
  padding: var(--nb-space-2) var(--nb-space-4);
  font-size: var(--nb-font-size-sm);
  font-weight: var(--nb-font-weight-medium);
  text-decoration: none;
  opacity: 0.85;
  transition: opacity var(--nb-transition-fast);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.header-nav .btn:hover,
.header-nav .btn-primary:hover,
.header-nav .btn-nav:hover,
.nb-header-nav .btn:hover,
.nb-header-nav .nb-btn:hover {
  opacity: 1;
  background: transparent !important;
  transform: none !important;
}

/* Active/current page - solid red background */
.header-nav .btn[aria-current="page"],
.header-nav .btn-primary[aria-current="page"],
.header-nav .btn-nav[aria-current="page"],
.nb-header-nav .btn[aria-current="page"],
.nb-header-nav .nb-btn[aria-current="page"] {
  background: var(--nb-brand-primary) !important;
  opacity: 1;
  border-radius: var(--nb-radius-full);
  box-shadow: var(--nb-shadow-brand) !important;
}

/* ============================================
   TABLES
   ============================================ */

.nb-table-container {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--nb-radius-lg);
  box-shadow: var(--nb-shadow-sm);
}

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

.nb-table th {
  padding: var(--nb-space-4);
  text-align: left;
  font-weight: var(--nb-font-weight-semibold);
  color: var(--nb-gray-600);
  background: var(--nb-gray-50);
  border-bottom: 2px solid var(--nb-gray-200);
  white-space: nowrap;
}

.nb-table td {
  padding: var(--nb-space-4);
  border-bottom: 1px solid var(--nb-gray-200);
  vertical-align: middle;
}

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

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

/* ============================================
   STAT CARDS
   ============================================ */

.nb-stat-card {
  background: var(--nb-white);
  border-radius: var(--nb-radius-lg);
  padding: var(--nb-space-6);
  box-shadow: var(--nb-shadow-sm);
  transition: all var(--nb-transition-normal);
}

.nb-stat-card:hover {
  box-shadow: var(--nb-shadow-md);
  transform: translateY(-2px);
}

.nb-stat-label {
  font-size: var(--nb-font-size-sm);
  font-weight: var(--nb-font-weight-medium);
  color: var(--nb-gray-500);
  margin-bottom: var(--nb-space-2);
}

.nb-stat-value {
  font-size: var(--nb-font-size-3xl);
  font-weight: var(--nb-font-weight-bold);
  color: var(--nb-gray-700);
  line-height: var(--nb-line-height-tight);
}

.nb-stat-change {
  font-size: var(--nb-font-size-xs);
  margin-top: var(--nb-space-2);
}

.nb-stat-change-up {
  color: var(--nb-success);
}

.nb-stat-change-down {
  color: var(--nb-error);
}

/* ============================================
   MODALS
   ============================================ */

.nb-modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  z-index: var(--nb-z-modal-backdrop);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--nb-space-4);
  opacity: 0;
  visibility: hidden;
  transition: all var(--nb-transition-normal);
}

.nb-modal-backdrop.open {
  opacity: 1;
  visibility: visible;
}

.nb-modal {
  background: var(--nb-white);
  border-radius: var(--nb-radius-xl);
  box-shadow: var(--nb-shadow-xl);
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow: hidden;
  transform: scale(0.95) translateY(10px);
  transition: transform var(--nb-transition-spring);
}

.nb-modal-backdrop.open .nb-modal {
  transform: scale(1) translateY(0);
}

.nb-modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--nb-space-5) var(--nb-space-6);
  border-bottom: 1px solid var(--nb-gray-200);
}

.nb-modal-title {
  font-size: var(--nb-font-size-lg);
  font-weight: var(--nb-font-weight-semibold);
  color: var(--nb-gray-700);
  margin: 0;
}

.nb-modal-close {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: var(--nb-radius-full);
  color: var(--nb-gray-500);
  font-size: 24px;
  cursor: pointer;
  transition: all var(--nb-transition-fast);
}

.nb-modal-close:hover {
  background: var(--nb-gray-100);
  color: var(--nb-gray-700);
}

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

.nb-modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: var(--nb-space-3);
  padding: var(--nb-space-4) var(--nb-space-6);
  border-top: 1px solid var(--nb-gray-200);
  background: var(--nb-gray-50);
}

/* ============================================
   TOASTS / NOTIFICATIONS
   ============================================ */

.nb-toast-container {
  position: fixed;
  top: var(--nb-space-6);
  right: var(--nb-space-6);
  z-index: var(--nb-z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--nb-space-3);
}

.nb-toast {
  display: flex;
  align-items: center;
  gap: var(--nb-space-3);
  padding: var(--nb-space-4) var(--nb-space-5);
  background: var(--nb-white);
  border-radius: var(--nb-radius-md);
  box-shadow: var(--nb-shadow-lg);
  min-width: 300px;
  max-width: 400px;
  animation: nb-toast-in var(--nb-transition-spring);
}

@keyframes nb-toast-in {
  from {
    opacity: 0;
    transform: translateX(100%);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.nb-toast-success {
  border-left: 4px solid var(--nb-success);
}

.nb-toast-error {
  border-left: 4px solid var(--nb-error);
}

.nb-toast-warning {
  border-left: 4px solid var(--nb-warning);
}

.nb-toast-info {
  border-left: 4px solid var(--nb-info);
}

.nb-toast-message {
  flex: 1;
  font-size: var(--nb-font-size-sm);
  color: var(--nb-gray-700);
}

/* ============================================
   BADGES / TAGS
   ============================================ */

.nb-badge {
  display: inline-flex;
  align-items: center;
  padding: var(--nb-space-1) var(--nb-space-3);
  font-size: var(--nb-font-size-xs);
  font-weight: var(--nb-font-weight-semibold);
  border-radius: var(--nb-radius-full);
  white-space: nowrap;
}

.nb-badge-primary {
  background: var(--nb-brand-lighter);
  color: var(--nb-brand-primary);
}

.nb-badge-success {
  background: var(--nb-success-light);
  color: var(--nb-success-dark);
}

.nb-badge-warning {
  background: var(--nb-warning-light);
  color: var(--nb-warning-dark);
}

.nb-badge-error {
  background: var(--nb-error-light);
  color: var(--nb-error-dark);
}

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

/* ============================================
   LOADING STATES
   ============================================ */

.nb-spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--nb-gray-200);
  border-top-color: var(--nb-brand-primary);
  border-radius: 50%;
  animation: nb-spin 0.8s linear infinite;
}

.nb-spinner-lg {
  width: 40px;
  height: 40px;
  border-width: 3px;
}

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

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

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

/* ============================================
   UTILITY CLASSES
   ============================================ */

/* Flexbox */
.nb-flex { display: flex; }
.nb-flex-col { flex-direction: column; }
.nb-items-center { align-items: center; }
.nb-justify-center { justify-content: center; }
.nb-justify-between { justify-content: space-between; }
.nb-gap-2 { gap: var(--nb-space-2); }
.nb-gap-4 { gap: var(--nb-space-4); }
.nb-gap-6 { gap: var(--nb-space-6); }

/* Grid */
.nb-grid { display: grid; }
.nb-grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.nb-grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.nb-grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* Spacing */
.nb-m-0 { margin: 0; }
.nb-mt-4 { margin-top: var(--nb-space-4); }
.nb-mb-4 { margin-bottom: var(--nb-space-4); }
.nb-p-4 { padding: var(--nb-space-4); }
.nb-p-6 { padding: var(--nb-space-6); }

/* Text */
.nb-text-center { text-align: center; }
.nb-text-sm { font-size: var(--nb-font-size-sm); }
.nb-text-lg { font-size: var(--nb-font-size-lg); }
.nb-font-medium { font-weight: var(--nb-font-weight-medium); }
.nb-font-semibold { font-weight: var(--nb-font-weight-semibold); }
.nb-text-muted { color: var(--nb-gray-500); }

/* Visibility */
.nb-hidden { display: none !important; }
.nb-sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ============================================
   RESPONSIVE UTILITIES
   ============================================ */

@media (max-width: 768px) {
  .nb-header-top {
    padding: var(--nb-space-3) var(--nb-space-4);
  }

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

  .nb-header-nav {
    padding: 0 var(--nb-space-4) var(--nb-space-3);
    overflow-x: auto;
    flex-wrap: nowrap;
    justify-content: flex-start;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .nb-header-nav::-webkit-scrollbar {
    display: none;
  }

  .nb-grid-cols-2,
  .nb-grid-cols-3,
  .nb-grid-cols-4 {
    grid-template-columns: 1fr;
  }

  .nb-modal {
    max-width: calc(100% - var(--nb-space-8));
    margin: var(--nb-space-4);
  }

  .nb-toast-container {
    left: var(--nb-space-4);
    right: var(--nb-space-4);
  }

  .nb-toast {
    min-width: auto;
    max-width: none;
  }
}

@media (max-width: 480px) {
  .nb-header-logo {
    height: 36px;
  }

  .nb-header-user {
    display: none;
  }

  .nb-btn {
    padding: var(--nb-space-3) var(--nb-space-4);
    font-size: var(--nb-font-size-xs);
  }
}

/* ============================================
   ACCESSIBILITY
   ============================================ */

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

/* High contrast focus rings */
*:focus-visible {
  outline: 3px solid var(--nb-brand-primary);
  outline-offset: 2px;
}

/* Skip link */
.nb-skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: var(--nb-brand-primary);
  color: var(--nb-white);
  padding: var(--nb-space-3) var(--nb-space-4);
  text-decoration: none;
  font-weight: var(--nb-font-weight-semibold);
  z-index: 10000;
  border-radius: 0 0 var(--nb-radius-sm) 0;
  transition: top var(--nb-transition-fast);
}

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