/* ==========================================================================
   OPEN TEXTBOOKS - UI/UX Enhancements v2.0
   Professional Academic Design - Navigation, Progress, Animations
   ========================================================================== */

/* ==========================================================================
   Typography Improvements
   ========================================================================== */

/* Better text sizing */
:root {
  --text-base-improved: 1.0625rem;  /* 17px for better readability */
}

body {
  font-size: var(--text-base-improved);
  letter-spacing: -0.01em;
}

/* Improved heading hierarchy */
h1 {
  font-size: clamp(2rem, 5vw, 2.75rem);
  letter-spacing: -0.025em;
  line-height: 1.15;
}

h2 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

h3 {
  font-size: clamp(1.25rem, 3vw, 1.5rem);
  letter-spacing: -0.015em;
}

/* Better paragraph spacing */
.lesson-content p,
.static-page p {
  line-height: 1.75;
  margin-bottom: 1.5em;
}

/* ==========================================================================
   Navigation Improvements
   ========================================================================== */

/* Sticky header with shrink effect */
.site-header {
  transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
}

/* Better nav link styling */
.nav-primary .nav-link {
  position: relative;
  font-weight: 500;
}

.nav-primary .nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--amber-400);
  transition: all var(--transition-fast);
  transform: translateX(-50%);
}

.nav-primary .nav-link:hover::after,
.nav-primary .nav-link.active::after {
  width: calc(100% - 1rem);
}

/* Grade navigation - better visual feedback */
.grades-scroll a {
  position: relative;
  font-weight: 600;
}

.grades-scroll a::before {
  content: '';
  position: absolute;
  inset: 4px;
  background: var(--amber-100);
  border-radius: var(--radius-md);
  opacity: 0;
  transform: scale(0.8);
  transition: all var(--transition-fast);
  z-index: -1;
}

.grades-scroll a:hover::before {
  opacity: 1;
  transform: scale(1);
}

.grades-scroll a.active {
  color: var(--amber-800);
}

.grades-scroll a.active::before {
  opacity: 1;
  transform: scale(1);
  background: var(--amber-200);
}

/* Current location indicator */
.breadcrumb-current {
  position: relative;
  padding-left: var(--space-3);
}

.breadcrumb-current::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 6px;
  background: var(--amber-500);
  border-radius: 50%;
}

/* ==========================================================================
   Progress Indicators
   ========================================================================== */

/* Progress bar */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--slate-200);
  border-radius: var(--radius-full);
  overflow: hidden;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.06);
}

.progress-bar__fill {
  height: 100%;
  background: linear-gradient(90deg, var(--sage-500), var(--sage-400));
  border-radius: var(--radius-full);
  transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}

.progress-bar__fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* Small progress bar variant */
.progress-bar--sm {
  height: 4px;
}

/* Unit progress on cards */
.unit-progress {
  margin-top: var(--space-3);
}

.unit-progress__label {
  display: flex;
  justify-content: space-between;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-bottom: var(--space-1);
}

/* Completion checkmark */
.lesson-complete-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  background: var(--sage-500);
  color: white;
  border-radius: 50%;
  font-size: 12px;
  margin-left: var(--space-2);
  animation: popIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes popIn {
  0% { transform: scale(0); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

/* Lesson card with completion state */
.lesson-card.completed {
  border-left: 3px solid var(--sage-500);
}

.lesson-card.completed .lesson-number {
  background: var(--sage-100);
  color: var(--sage-700);
}

/* Subject card progress */
.subject-card-progress {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-4);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-border);
}

.subject-card-progress__text {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  white-space: nowrap;
}

.subject-card-progress .progress-bar {
  flex: 1;
  height: 6px;
}

/* ==========================================================================
   Animations & Transitions
   ========================================================================== */

/* Page load animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Main content fade in */
.main-content {
  animation: fadeInUp 0.4s ease-out;
}

/* Staggered card animations */
.subjects-grid .subject-card,
.units-grid .unit-card,
.lessons-list .lesson-card,
.grades-grid .grade-card {
  opacity: 0;
  animation: fadeInUp 0.5s ease-out forwards;
}

.subjects-grid .subject-card:nth-child(1),
.grades-grid .grade-card:nth-child(1) { animation-delay: 0.05s; }
.subjects-grid .subject-card:nth-child(2),
.grades-grid .grade-card:nth-child(2) { animation-delay: 0.1s; }
.subjects-grid .subject-card:nth-child(3),
.grades-grid .grade-card:nth-child(3) { animation-delay: 0.15s; }
.subjects-grid .subject-card:nth-child(4),
.grades-grid .grade-card:nth-child(4) { animation-delay: 0.2s; }
.subjects-grid .subject-card:nth-child(5),
.grades-grid .grade-card:nth-child(5) { animation-delay: 0.25s; }

.units-grid .unit-card:nth-child(1) { animation-delay: 0.05s; }
.units-grid .unit-card:nth-child(2) { animation-delay: 0.1s; }
.units-grid .unit-card:nth-child(3) { animation-delay: 0.15s; }
.units-grid .unit-card:nth-child(4) { animation-delay: 0.2s; }
.units-grid .unit-card:nth-child(5) { animation-delay: 0.25s; }
.units-grid .unit-card:nth-child(6) { animation-delay: 0.3s; }

.lessons-list .lesson-card:nth-child(1) { animation-delay: 0.03s; }
.lessons-list .lesson-card:nth-child(2) { animation-delay: 0.06s; }
.lessons-list .lesson-card:nth-child(3) { animation-delay: 0.09s; }
.lessons-list .lesson-card:nth-child(4) { animation-delay: 0.12s; }
.lessons-list .lesson-card:nth-child(5) { animation-delay: 0.15s; }
.lessons-list .lesson-card:nth-child(6) { animation-delay: 0.18s; }

/* Card hover effects - smoother */
.subject-card,
.unit-card,
.lesson-card,
.grade-card {
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow 0.25s cubic-bezier(0.4, 0, 0.2, 1),
              border-color 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.subject-card:hover,
.grade-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px -8px rgba(0, 0, 0, 0.12);
}

.unit-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 16px -6px rgba(0, 0, 0, 0.1);
}

.lesson-card:hover {
  transform: translateX(4px);
}

/* Button hover animations */
.btn {
  transition: transform 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              box-shadow 0.2s cubic-bezier(0.4, 0, 0.2, 1),
              background-color 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

/* Link hover effect */
.breadcrumb a,
.lesson-navigation a {
  transition: color 0.15s ease, transform 0.15s ease;
}

.breadcrumb a:hover {
  color: var(--amber-700);
}

/* ==========================================================================
   Visual Design Refinements
   ========================================================================== */

/* Better card styling */
.subject-card,
.unit-card {
  background: linear-gradient(180deg, var(--color-bg-elevated) 0%, var(--slate-50) 100%);
  border: 1px solid var(--color-border);
}

.subject-card:hover,
.unit-card:hover {
  border-color: var(--amber-300);
  background: var(--color-bg-elevated);
}

/* Page header with subtle gradient */
.page-header {
  background: linear-gradient(180deg, #f1f5f9 0%, transparent 100%);
  padding: var(--space-8) 0;
  margin-bottom: var(--space-8);
  border-bottom: 1px solid var(--color-border);
}

/* Lesson meta box refinement */
.lesson-meta-box {
  background: linear-gradient(135deg, #f8fafc 0%, #fffbeb 100%);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

/* Better section dividers */
.lesson-section {
  position: relative;
  padding-bottom: var(--space-10);
  margin-bottom: var(--space-10);
}

.lesson-section::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border), transparent);
}

.lesson-section:last-of-type::after {
  display: none;
}

/* Feature cards on homepage */
.feature-card {
  background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
  border: 1px solid var(--color-border);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] .feature-card {
  background: linear-gradient(180deg, var(--color-bg-elevated) 0%, var(--color-surface) 100%);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 32px -8px rgba(0, 0, 0, 0.1);
  border-color: var(--amber-200);
}

[data-theme="dark"] .feature-card:hover {
  box-shadow: 0 16px 32px -8px rgba(0, 0, 0, 0.4);
}

/* ==========================================================================
   Continue Where You Left Off Banner
   ========================================================================== */
.continue-banner {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  background: linear-gradient(135deg, var(--amber-50) 0%, var(--amber-100) 100%);
  border: 1px solid var(--amber-200);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-6);
  animation: fadeInUp 0.4s ease-out;
}

.continue-banner__icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

.continue-banner__content {
  flex: 1;
}

.continue-banner__label {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--amber-700);
  font-weight: 600;
  margin-bottom: var(--space-1);
}

.continue-banner__title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-heading);
}

.continue-banner__link {
  flex-shrink: 0;
}

/* ==========================================================================
   Back to Top Button
   ========================================================================== */
.back-to-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 48px;
  height: 48px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: var(--z-fixed);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--amber-500);
  border-color: var(--amber-500);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px -4px rgba(245, 158, 11, 0.4);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

/* ==========================================================================
   Footer Improvements
   ========================================================================== */
.site-footer {
  position: relative;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--amber-400), var(--amber-500), var(--amber-400));
}

.footer-content {
  padding: var(--space-8) var(--space-4);
}

/* ==========================================================================
   Print Optimizations
   ========================================================================== */
@media print {
  .back-to-top,
  .continue-banner,
  .progress-bar {
    display: none !important;
  }
}

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

  .subject-card,
  .unit-card,
  .lesson-card,
  .grade-card,
  .feature-card {
    opacity: 1;
    animation: none;
  }
}

/* ==========================================================================
   Dark Mode Adjustments
   ========================================================================== */
[data-theme="dark"] .subject-card,
[data-theme="dark"] .unit-card,
[data-theme="dark"] .feature-card {
  background: var(--color-bg-elevated);
}

[data-theme="dark"] .page-header {
  background: linear-gradient(180deg, rgba(45, 55, 72, 0.6) 0%, transparent 100%);
}

[data-theme="dark"] .lesson-meta-box {
  background: var(--color-bg-elevated);
}

[data-theme="dark"] .alignment-box {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
}

[data-theme="dark"] .alignment-box h3 {
  color: var(--amber-400);
}

[data-theme="dark"] .continue-banner {
  background: linear-gradient(135deg, var(--amber-900) 0%, var(--amber-800) 100%);
  border-color: var(--amber-700);
}

[data-theme="dark"] .back-to-top {
  background: var(--slate-800);
  border-color: var(--slate-700);
}

[data-theme="dark"] .progress-bar {
  background: var(--slate-700);
}

/* ==========================================================================
   About/Contact Page Styles
   ========================================================================== */
.about-section {
  margin-bottom: var(--space-10);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid var(--color-border);
}

.about-section:last-of-type {
  border-bottom: none;
  margin-bottom: 0;
}

.team-note {
  background: linear-gradient(135deg, var(--amber-50) 0%, var(--slate-50) 100%);
  border: 1px solid var(--amber-200);
  border-left: 4px solid var(--amber-400);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin: var(--space-4) 0;
}

.team-note p:first-child {
  font-size: var(--text-lg);
  color: var(--color-heading);
  margin-bottom: var(--space-4);
}

.response-note {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}

.thank-you-section {
  background: linear-gradient(135deg, var(--sage-50) 0%, var(--slate-50) 100%);
  border: 1px solid var(--sage-200);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  text-align: center;
}

.thank-you-section h2 {
  color: var(--sage-700);
}

/* ==========================================================================
   Partnership Page Styles
   ========================================================================== */
.partnership-intro {
  background: linear-gradient(135deg, var(--navy-50, var(--slate-100)) 0%, var(--slate-50) 100%);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  margin-bottom: var(--space-8);
  text-align: center;
}

.partnership-intro h2 {
  color: var(--navy-800, var(--slate-800));
  margin-bottom: var(--space-4);
}

.partner-types {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
  margin: var(--space-8) 0;
}

.partner-type-card {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: all 0.3s ease;
}

.partner-type-card:hover {
  border-color: var(--amber-300);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.partner-type-card h3 {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}

.partner-type-card h3 span {
  font-size: 1.5rem;
}

/* Contact Form Styles */
.contact-form {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  margin-top: var(--space-8);
}

.contact-form h2 {
  margin-bottom: var(--space-6);
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-4);
}

.form-group {
  margin-bottom: var(--space-5);
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--color-heading);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--amber-400);
  box-shadow: 0 0 0 3px var(--amber-100);
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

.form-group .required {
  color: var(--rose-500);
}

.form-submit {
  display: flex;
  justify-content: center;
  margin-top: var(--space-6);
}

.form-note {
  text-align: center;
  margin-top: var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* Dark mode */
[data-theme="dark"] .team-note {
  background: linear-gradient(135deg, var(--amber-900) 0%, var(--slate-800) 100%);
  border-color: var(--amber-700);
}

[data-theme="dark"] .thank-you-section {
  background: linear-gradient(135deg, rgba(34, 197, 94, 0.1) 0%, var(--slate-800) 100%);
  border-color: var(--sage-700);
}

[data-theme="dark"] .partnership-intro {
  background: var(--slate-800);
}

[data-theme="dark"] .contact-form {
  background: var(--slate-800);
}