/* ==========================================================================
   UI/UX ENHANCEMENTS FOR NCERTBOOKS.NET
   Modern improvements for better user experience
   ========================================================================== */

/* -------------------------
   PERFORMANCE & LOADING STATES
   ------------------------- */
.loading-skeleton {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: loading 1.5s ease-in-out infinite;
  border-radius: var(--radius-md);
}

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

/* Smooth page transitions */
.page-transition {
  opacity: 0;
  animation: fadeIn 0.3s ease-in forwards;
}

@keyframes fadeIn {
  to { opacity: 1; }
}

/* -------------------------
   ENHANCED MOBILE EXPERIENCE
   ------------------------- */
@media (max-width: 768px) {
  /* Larger touch targets */
  .btn, .nav-link, .download-btn, a[role="button"] {
    min-height: 44px;
    min-width: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  /* Better spacing on mobile */
  .container {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  /* Improved table scrolling */
  .table-responsive {
    -webkit-overflow-scrolling: touch;
    scrollbar-width: thin;
  }

  /* Better card spacing */
  .card {
    margin-bottom: 1rem;
  }

  /* Improved form inputs */
  input[type="search"],
  input[type="text"],
  input[type="email"],
  textarea,
  select {
    font-size: 16px; /* Prevents zoom on iOS */
    padding: 0.75rem;
    border-radius: var(--radius-md);
  }
}

/* -------------------------
   ENHANCED NAVIGATION
   ------------------------- */
/* Smooth scroll behavior */
html {
  scroll-behavior: smooth;
}

/* Sticky header enhancement */
.navbar.sticky-top {
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}

.navbar.scrolled {
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* Active navigation indicator */
.nav-link.active {
  position: relative;
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 80%;
  height: 3px;
  background: var(--bs-primary);
  border-radius: 3px 3px 0 0;
}

/* -------------------------
   ENHANCED SEARCH
   ------------------------- */
.search-container {
  position: relative;
}

.search-suggestions {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: white;
  border: 1px solid var(--bs-gray-300);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  max-height: 400px;
  overflow-y: auto;
  z-index: 1000;
  margin-top: 0.5rem;
  display: none;
}

.search-suggestions.active {
  display: block;
}

.search-suggestion-item {
  padding: 0.75rem 1rem;
  cursor: pointer;
  transition: background 0.2s ease;
  border-bottom: 1px solid var(--bs-gray-200);
}

.search-suggestion-item:last-child {
  border-bottom: none;
}

.search-suggestion-item:hover,
.search-suggestion-item:focus {
  background: var(--bs-gray-100);
  outline: none;
}

.search-suggestion-item.highlight {
  background: rgba(var(--bs-primary-rgb), 0.1);
}

/* Search input focus enhancement */
.form-control:focus {
  border-color: var(--bs-primary);
  box-shadow: 0 0 0 0.2rem rgba(var(--bs-primary-rgb), 0.25);
}

/* -------------------------
   ENHANCED TABLES
   ------------------------- */
/* Better table hover effects */
.table tbody tr {
  transition: all 0.2s ease;
}

.table tbody tr:hover {
  background-color: rgba(var(--bs-primary-rgb), 0.05);
  transform: scale(1.01);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

/* Improved table headers */
.table thead th {
  position: sticky;
  top: 0;
  z-index: 10;
  background: #cfe2ff;
}

/* Table row selection */
.table tbody tr.selected {
  background-color: rgba(var(--bs-primary-rgb), 0.15);
  border-left: 3px solid var(--bs-primary);
}

/* Better table spacing */
.table td,
.table th {
  padding: 1rem 0.75rem;
  vertical-align: middle;
}

/* -------------------------
   ENHANCED BUTTONS
   ------------------------- */
.btn {
  position: relative;
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn:active::before {
  width: 300px;
  height: 300px;
}

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

/* Download button enhancements */
.download-btn {
  position: relative;
  overflow: hidden;
}

.download-btn::after {
  content: '⬇️';
  margin-left: 0.5rem;
  transition: transform 0.3s ease;
}

.download-btn:hover::after {
  transform: translateY(2px);
}

.download-btn.downloading::after {
  content: '⏳';
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* -------------------------
   ENHANCED CARDS
   ------------------------- */
.card {
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid var(--bs-gray-200);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
  border-color: var(--bs-primary);
}

.card-img-top {
  transition: transform 0.3s ease;
}

.card:hover .card-img-top {
  transform: scale(1.05);
}

/* Card loading state */
.card.loading {
  pointer-events: none;
  opacity: 0.6;
}

/* -------------------------
   ENHANCED FORMS
   ------------------------- */
.form-control {
  transition: all 0.2s ease;
}

.form-control:focus {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(var(--bs-primary-rgb), 0.15);
}

.form-label {
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--bs-gray-700);
}

/* Input validation states */
.form-control.is-valid {
  border-color: var(--bs-success);
}

.form-control.is-invalid {
  border-color: var(--bs-danger);
}

/* -------------------------
   ENHANCED BREADCRUMBS
   ------------------------- */
.breadcrumb {
  background: transparent;
  padding: 0.75rem 0;
}

.breadcrumb-item {
  display: flex;
  align-items: center;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: '›';
  padding: 0 0.5rem;
  color: var(--bs-gray-500);
  font-weight: bold;
}

.breadcrumb-item a {
  color: var(--bs-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.breadcrumb-item a:hover {
  color: var(--bs-primary);
  text-decoration: underline;
}

.breadcrumb-item.active {
  color: var(--bs-gray-600);
  font-weight: 500;
}

/* -------------------------
   ENHANCED MODALS & POPOVERS
   ------------------------- */
.modal {
  backdrop-filter: blur(4px);
}

.modal-content {
  border: none;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  border-radius: var(--radius-xl);
}

.modal-header {
  border-bottom: 1px solid var(--bs-gray-200);
  padding: 1.5rem;
}

.modal-body {
  padding: 1.5rem;
}

.modal-footer {
  border-top: 1px solid var(--bs-gray-200);
  padding: 1rem 1.5rem;
}

/* -------------------------
   ENHANCED ACCORDION
   ------------------------- */
.accordion-button {
  transition: all 0.2s ease;
}

.accordion-button:not(.collapsed) {
  background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
  color: var(--bs-primary);
}

.accordion-button:focus {
  box-shadow: 0 0 0 0.25rem rgba(var(--bs-primary-rgb), 0.25);
}

.accordion-body {
  transition: all 0.3s ease;
}

/* -------------------------
   ENHANCED ALERTS
   ------------------------- */
.alert {
  border: none;
  border-left: 4px solid;
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  box-shadow: var(--shadow-sm);
}

.alert-dismissible .btn-close {
  padding: 0.75rem;
}

/* -------------------------
   ENHANCED PAGINATION
   ------------------------- */
.pagination {
  gap: 0.5rem;
}

.page-link {
  border-radius: var(--radius-md);
  border: 1px solid var(--bs-gray-300);
  padding: 0.5rem 0.75rem;
  transition: all 0.2s ease;
}

.page-link:hover {
  background: var(--bs-primary);
  color: white;
  border-color: var(--bs-primary);
  transform: translateY(-2px);
}

.page-item.active .page-link {
  background: var(--bs-primary);
  border-color: var(--bs-primary);
  box-shadow: 0 2px 8px rgba(var(--bs-primary-rgb), 0.3);
}

/* -------------------------
   ENHANCED TOOLTIPS
   ------------------------- */
.tooltip {
  font-size: 0.875rem;
}

.tooltip-inner {
  background: var(--bs-gray-900);
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-md);
}

/* -------------------------
   ENHANCED SCROLLBAR
   ------------------------- */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bs-gray-100);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb {
  background: var(--bs-gray-400);
  border-radius: 5px;
  transition: background 0.2s ease;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--bs-primary);
}

/* Firefox scrollbar */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--bs-gray-400) var(--bs-gray-100);
}

/* -------------------------
   ENHANCED ACCESSIBILITY
   ------------------------- */
/* Skip link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--bs-primary);
  color: white;
  padding: 0.5rem 1rem;
  text-decoration: none;
  z-index: 10000;
  border-radius: 0 0 var(--radius-md) 0;
}

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

/* Focus visible improvements */
*:focus-visible {
  outline: 2px solid var(--bs-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* Screen reader only */
.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;
}

/* -------------------------
   ENHANCED ANIMATIONS
   ------------------------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.5s ease-out;
}

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

.slide-in-right {
  animation: slideInRight 0.3s ease-out;
}

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

/* -------------------------
   ENHANCED PRINT STYLES
   ------------------------- */
@media print {
  .navbar,
  .sidebar,
  footer,
  .btn,
  .breadcrumb,
  .pagination {
    display: none !important;
  }

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

  .table {
    border-collapse: collapse;
  }

  .table th,
  .table td {
    border: 1px solid #000;
    padding: 0.5rem;
  }

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
    color: #666;
  }
}

/* -------------------------
   ENHANCED UTILITIES
   ------------------------- */
.text-shadow {
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.box-shadow-sm {
  box-shadow: var(--shadow-sm);
}

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

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

.transition-all {
  transition: all 0.3s ease;
}

.cursor-pointer {
  cursor: pointer;
}

.user-select-none {
  user-select: none;
}

.user-select-text {
  user-select: text;
}

/* -------------------------
   ENHANCED RESPONSIVE HELPERS
   ------------------------- */
@media (max-width: 576px) {
  .container-fluid {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
  h4 { font-size: 1.125rem; }
}

/* -------------------------
   ENHANCED DARK MODE SUPPORT (Future)
   ------------------------- */
@media (prefers-color-scheme: dark) {
  /* Dark mode styles can be added here */
}

/* -------------------------
   ENHANCED PERFORMANCE
   ------------------------- */
/* Will-change for animations */
.card,
.btn,
.nav-link {
  will-change: transform;
}

/* GPU acceleration */
.card:hover,
.btn:hover {
  transform: translateZ(0);
}

/* -------------------------
   ENHANCED ERROR STATES
   ------------------------- */
.error-message {
  color: var(--bs-danger);
  font-size: 0.875rem;
  margin-top: 0.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.error-message::before {
  content: '⚠️';
}

.success-message {
  color: var(--bs-success);
  font-size: 0.875rem;
  margin-top: 0.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.success-message::before {
  content: '✓';
}

/* -------------------------
   ENHANCED LOADING SPINNER
   ------------------------- */
.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(var(--bs-primary-rgb), 0.3);
  border-radius: 50%;
  border-top-color: var(--bs-primary);
  animation: spin 1s ease-in-out infinite;
}

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

.spinner-lg {
  width: 40px;
  height: 40px;
  border-width: 4px;
}

.spinner-sm {
  width: 16px;
  height: 16px;
  border-width: 2px;
}