/* ==========================================================================
   TOPICS PAGE - PREMIUM GCSE MATHS ROADMAP
   Matching Exam Bank design system for consistency
   ========================================================================== */

/* Page Header */
.page-header {
  background: linear-gradient(135deg, #F0F4FF 0%, #FFFFFF 100%);
  padding: 3rem 0 2.5rem;
  border-bottom: 1px solid var(--color-border-light);
}

.page-title {
  font-size: clamp(2rem, 4vw, 2.5rem);
  margin-bottom: 0.75rem;
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  line-height: 1.2;
  text-align: center;
}

.page-subtitle {
  color: var(--color-text-secondary);
  font-size: var(--text-lg);
  max-width: 700px;
  line-height: 1.6;
  text-align: center;
  margin: 0 auto;
}

/* Main Container */
main {
  padding: 2.5rem 0 4rem;
  background: var(--color-bg-secondary);
  min-height: 60vh;
}

/* Filters Section */
.filters-section {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
}

.filter-row {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  align-items: flex-start;
}

.filter-label {
  font-weight: var(--font-weight-semibold);
  min-width: 100px;
  color: var(--color-text-primary);
  font-size: var(--text-base);
  padding-top: 0.5rem;
}

.filter-group {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  flex: 1;
}

.filter-chip {
  padding: 0.625rem 1.25rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-full);
  background: white;
  cursor: pointer;
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  transition: all var(--transition-fast);
  color: var(--color-text-primary);
  white-space: nowrap;
}

.filter-chip:hover {
  border-color: var(--color-primary);
  background: var(--color-bg-secondary);
  transform: translateY(-1px);
}

.filter-chip.active {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

/* Topic Sections */
.topic-section {
  margin-bottom: 3rem;
}

.topic-section-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--color-border-light);
}

.topic-section-icon {
  font-size: 2rem;
}

.topic-section-title {
  font-size: var(--text-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

.topic-section-count {
  margin-left: auto;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
}

/* Topics Grid */
.topics-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: 1fr;
}

/* Topic Card */
.topic-card {
  background: white;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  text-decoration: none;
  display: block;
}

.topic-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.topic-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 1rem;
  gap: 1rem;
}

.topic-card-title-group {
  flex: 1;
}

.topic-meta-badges {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.topic-badge {
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.025em;
}

.badge-foundation {
  background: #FEF3C7;
  color: #92400E;
}

.badge-higher {
  background: #FEE2E2;
  color: #991B1B;
}

.badge-both {
  background: #E0E7FF;
  color: #4338CA;
}

.badge-free {
  background: #D1FAE5;
  color: #065F46;
  font-weight: var(--font-weight-bold);
}

.badge-locked {
  background: #FEE2E2;
  color: #991B1B;
  font-weight: var(--font-weight-bold);
}

/* Locked Topic Cards */
.topic-card-locked {
  opacity: 0.6;
  cursor: pointer;
  position: relative;
}

.topic-card-locked::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-lg);
  pointer-events: none;
}

.topic-card-locked:hover {
  opacity: 0.8;
  border-color: #EF4444;
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.15);
}

.topic-card-locked .topic-action {
  background: #EF4444;
  color: white;
}

.topic-card-locked .topic-action:hover {
  background: #DC2626;
}


.topic-card-title {
  font-size: var(--text-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.topic-card-subtitle {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  line-height: 1.5;
  margin-bottom: 1rem;
}

.topic-card-icon {
  font-size: 2rem;
  opacity: 0.3;
  transition: opacity var(--transition-fast);
}

.topic-card:hover .topic-card-icon {
  opacity: 0.6;
}

/* Skills List */
.topic-skills {
  margin: 1.25rem 0;
  padding: 1.25rem;
  background: var(--color-bg-secondary);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--color-primary);
}

.topic-skills-title {
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.topic-skills-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.topic-skills-list li {
  color: var(--color-text-primary);
  font-size: var(--text-sm);
  line-height: 1.5;
  padding-left: 1.5rem;
  position: relative;
}

.topic-skills-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-success);
  font-weight: var(--font-weight-bold);
}

/* Value Signals */
.topic-value-signals {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border-light);
}

.value-signal {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  font-weight: var(--font-weight-medium);
}

.value-signal-icon {
  font-size: 1rem;
}

/* Action Button */
.topic-action {
  margin-top: 1rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  width: 100%;
  justify-content: center;
}

.topic-action:hover {
  background: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.topic-action .arrow {
  transition: transform var(--transition-fast);
}

.topic-card:hover .topic-action .arrow {
  transform: translateX(3px);
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 4rem 1rem;
}

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

.empty-state h3 {
  font-size: var(--text-xl);
  font-weight: var(--font-weight-semibold);
  margin-bottom: 0.5rem;
  color: var(--color-text-primary);
}

.empty-state p {
  color: var(--color-text-secondary);
  font-size: var(--text-base);
}

/* Progress Indicator */
.topic-progress {
  margin-top: 1rem;
  padding: 1rem;
  background: #F0FDF4;
  border: 1px solid #BBF7D0;
  border-radius: var(--radius-md);
  display: none;
}

.topic-progress.show {
  display: block;
}

.progress-text {
  color: #065F46;
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Responsive Design */
@media (min-width: 768px) {
  .topics-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-header {
    padding: 3.5rem 0 3rem;
  }
}

@media (min-width: 1024px) {
  .topics-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .page-header {
    padding: 2rem 0 1.5rem;
  }

  .page-title {
    font-size: 1.75rem;
  }

  .page-subtitle {
    font-size: var(--text-base);
  }

  .filters-section {
    padding: 1.25rem;
  }

  .filter-row {
    flex-direction: column;
    gap: 1rem;
  }

  .filter-label {
    min-width: auto;
    padding-top: 0;
  }

  .filter-group {
    gap: 0.5rem;
  }

  .filter-chip {
    padding: 0.5rem 1rem;
    font-size: 0.813rem;
  }

  .topic-card {
    padding: 1.25rem;
  }

  .topic-card-header {
    flex-direction: column;
  }

  .topic-card-icon {
    font-size: 1.5rem;
  }

  .topic-skills {
    padding: 1rem;
  }

  .topic-value-signals {
    gap: 0.75rem;
  }
}

/* Free Plan Notice */
.free-plan-notice {
  background: linear-gradient(135deg, #FEF3C7 0%, #FDE68A 100%);
  border: 2px solid #F59E0B;
  border-radius: var(--radius-lg);
  padding: 1rem 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 2px 8px rgba(245, 158, 11, 0.15);
}

.free-plan-content {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  font-size: var(--text-base);
}

.free-plan-icon {
  font-size: 1.25rem;
}

.free-plan-text {
  font-weight: var(--font-weight-semibold);
  color: #92400E;
}

.free-plan-divider {
  color: #D97706;
  font-weight: var(--font-weight-bold);
}

.free-plan-upgrade {
  color: #DC2626;
  font-weight: var(--font-weight-bold);
  text-decoration: underline;
  transition: all var(--transition-fast);
}

.free-plan-upgrade:hover {
  color: #B91C1C;
  text-decoration: none;
}

/* Small Mobile - Reduce Container Padding */
@media (max-width: 480px) {
  main {
    padding: 1.25rem 0 2rem !important;
  }
  
  /* Eliminate ALL spacing before locked section */
  .topic-section:last-of-type {
    margin-bottom: 1rem !important;
  }
  
  #topics-container {
    margin-bottom: 0 !important;
    padding-bottom: 0 !important;
  }
}

/* Print Styles */
@media print {
  .filters-section,
  .topic-action {
    display: none;
  }

  .topic-card {
    page-break-inside: avoid;
    border: 1px solid #ccc;
    margin-bottom: 1rem;
  }
}