/* ==========================================================================
   EXAM BANK - PREMIUM GCSE PRACTICE SYSTEM
   Professional, structured, trust-building interface for paid subscriptions
   ========================================================================== */

/* ========== 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);
}

.breadcrumb {
  margin-bottom: 1rem;
  display: flex;
  gap: 0.5rem;
  align-items: center;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

.breadcrumb a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.breadcrumb a:hover {
  color: var(--color-primary-dark);
}

.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;
}

.page-subtitle {
  color: var(--color-text-secondary);
  font-size: var(--text-lg);
  max-width: 700px;
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

/* Trust Signals */
.trust-signals {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.trust-signal {
  display: inline-flex;
  align-items: center;
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-success);
}

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

/* ========== FILTER CONTROL PANEL ========== */
.filter-panel {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-sm);
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.75rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--color-border-light);
}

.panel-title {
  font-size: var(--text-xl);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin: 0;
}

.results-info {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  font-weight: var(--font-weight-medium);
}

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

.filter-row:last-of-type {
  margin-bottom: 0;
}

.filter-label {
  font-weight: var(--font-weight-semibold);
  min-width: 80px;
  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-md);
  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);
}

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

.results-count {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  margin-top: 0.75rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border-light);
}

/* ========== QUESTIONS GRID ========== */
.questions-grid {
  display: grid;
  gap: 1.5rem;
}

/* ========== QUESTION CARD (PREMIUM PRACTICE UNIT) ========== */
.question-card {
  background: white;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 0;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.question-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-md);
}

.question-card.expanded {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-lg);
}

/* Question Header */
.question-header {
  padding: 1.75rem;
  cursor: pointer;
  user-select: none;
  background: white;
  transition: background var(--transition-fast);
}

.question-header:hover {
  background: var(--color-bg-secondary);
}

.question-card.expanded .question-header {
  border-bottom: 1px solid var(--color-border-light);
  background: var(--color-bg-secondary);
}

/* Question Number Badge - CRITICAL FEATURE */
.question-number-badge {
  margin-bottom: 1rem;
}

.question-number {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: var(--color-primary);
  color: white;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-bold);
  letter-spacing: 0.025em;
}

/* Question Metadata */
.question-meta {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}

.meta-badge {
  padding: 0.375rem 0.875rem;
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.025em;
}

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

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

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

.badge-marks {
  background: #D1FAE5;
  color: #065F46;
}

.question-text {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.question-expand-btn {
  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);
}

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

.question-expand-btn .arrow {
  transition: transform var(--transition-fast);
}

.question-card.expanded .question-expand-btn .arrow {
  transform: rotate(180deg);
}

/* Question Content (Expanded) */
.question-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out;
}

.question-content.expanded {
  max-height: 3000px;
  transition: max-height 0.5s ease-in;
}

.question-inner {
  padding: 0 1.5rem 1.5rem;
  border-top: 1px solid var(--color-border-light);
}

/* Answer Input Area */
.answer-section {
  margin: 1.5rem 0;
  padding: 1.5rem;
  background: var(--color-bg-secondary);
  border-radius: var(--radius-md);
}

.answer-label {
  display: block;
  font-weight: var(--font-weight-semibold);
  margin-bottom: 0.75rem;
  color: var(--color-text-primary);
}

.answer-input {
  width: 100%;
  max-width: 400px;
  padding: 0.75rem 1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  transition: border-color var(--transition-fast);
}

.answer-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.answer-input.correct {
  border-color: var(--color-success);
  background: #F0FDF4;
}

.answer-input.incorrect {
  border-color: var(--color-error);
  background: #FEF2F2;
}

.answer-check-btn {
  margin-top: 0.75rem;
  padding: 0.75rem 1.5rem;
  background: var(--color-secondary);
  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);
}

.answer-check-btn:hover {
  background: var(--color-secondary-dark);
  transform: translateY(-1px);
}

.answer-check-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* Feedback Box */
.feedback-box {
  margin-top: 1rem;
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  line-height: 1.6;
  display: none;
}

.feedback-box.show {
  display: block;
  animation: slideDown 0.3s ease-out;
}

.feedback-box.correct {
  background: #F0FDF4;
  border: 2px solid var(--color-success);
  color: #065F46;
}

.feedback-box.incorrect {
  background: #FEF2F2;
  border: 2px solid var(--color-error);
  color: #991B1B;
}

.feedback-icon {
  font-size: 1.25rem;
  margin-right: 0.5rem;
}

/* Help Buttons */
.help-buttons {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.help-btn {
  padding: 0.625rem 1rem;
  background: white;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

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

.help-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

.help-btn .icon {
  font-size: 1.125rem;
}

/* Help Content */
.help-content {
  margin-bottom: 1.5rem;
  padding: 1.25rem;
  background: #FFFBEB;
  border: 2px solid #FDE68A;
  border-radius: var(--radius-md);
  display: none;
  animation: slideDown 0.3s ease-out;
}

.help-content.show {
  display: block;
}

.help-content h4 {
  font-size: var(--text-base);
  font-weight: var(--font-weight-semibold);
  margin-bottom: 0.75rem;
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.help-content p, .help-content ol, .help-content ul {
  color: var(--color-text-primary);
  line-height: 1.6;
}

.help-content ol, .help-content ul {
  margin-left: 1.5rem;
  margin-top: 0.5rem;
}

.help-content li {
  margin-bottom: 0.5rem;
}

.help-content.hint {
  background: #EFF6FF;
  border-color: #BFDBFE;
}

.help-content.mistake {
  background: #FEF2F2;
  border-color: #FECACA;
}

.help-content.tip {
  background: #F0FDF4;
  border-color: #BBF7D0;
}

/* Solution Section */
.solution-section {
  margin-top: 1.5rem;
  padding: 1.5rem;
  background: var(--color-bg-secondary);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  display: none;
}

.solution-section.show {
  display: block;
  animation: slideDown 0.3s ease-out;
}

.solution-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--color-border-light);
}

.solution-icon {
  font-size: 1.5rem;
}

.solution-header h4 {
  font-size: var(--text-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
}

.solution-steps {
  margin-top: 1rem;
}

.solution-step {
  padding: 1rem;
  background: white;
  border-radius: var(--radius-md);
  margin-bottom: 1rem;
}

.solution-step:last-child {
  margin-bottom: 0;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  font-size: var(--text-sm);
  font-weight: var(--font-weight-bold);
  margin-right: 0.75rem;
}

.step-text {
  display: inline;
  color: var(--color-text-primary);
  line-height: 1.6;
}

.step-working {
  margin-top: 0.5rem;
  margin-left: 2.25rem;
  padding: 0.75rem 1rem;
  background: var(--color-bg-secondary);
  border-left: 3px solid var(--color-primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-family: 'Courier New', monospace;
  color: var(--color-text-primary);
}

.final-answer {
  margin-top: 1rem;
  padding: 1rem 1.25rem;
  background: #F0FDF4;
  border: 2px solid var(--color-success);
  border-radius: var(--radius-md);
  font-weight: var(--font-weight-semibold);
  color: #065F46;
}

/* 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);
}

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

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

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

  .page-subtitle {
    font-size: var(--text-base);
  }
  
  .trust-signals {
    gap: 0.75rem;
  }
  
  .trust-signal {
    font-size: 0.813rem;
  }

  .filter-panel {
    padding: 1.25rem;
    margin-bottom: 2rem;
  }
  
  .panel-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 1.25rem;
    padding-bottom: 1rem;
  }
  
  .panel-title {
    font-size: var(--text-lg);
  }

  .filter-row {
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 1.25rem;
  }

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

  .filter-group {
    gap: 0.5rem;
  }

  .filter-chip {
    padding: 0.5rem 1rem;
    font-size: 0.813rem;
  }
  
  /* Tier filter (Foundation/Higher) - Premium mobile toggle */
  .filter-row:has([data-difficulty]) .filter-group {
    display: flex;
    gap: 8px;
    margin-top: 4px;
  }
  
  .filter-row:has([data-difficulty]) .filter-chip {
    flex: 1;
    height: 44px;
    padding: 0 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    font-size: 14px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .question-header {
    padding: 1.25rem;
  }
  
  .question-number {
    font-size: 0.813rem;
    padding: 0.5rem 0.875rem;
  }

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

  .question-inner {
    padding: 0 1.25rem 1.25rem;
  }

  .help-buttons {
    gap: 0.5rem;
  }

  .help-btn {
    padding: 0.5rem 0.875rem;
    font-size: 0.813rem;
  }

  .answer-input {
    max-width: 100%;
  }

  .solution-step {
    padding: 0.875rem;
  }

  .step-working {
    margin-left: 0;
    margin-top: 0.75rem;
    font-size: 0.875rem;
  }
}

/* Small Mobile - Extra Polish for Tier Toggle */
@media (max-width: 480px) {
  .filter-row:has([data-difficulty]) {
    margin-bottom: 1rem;
  }
  
  .filter-row:has([data-difficulty]) .filter-label {
    font-size: 0.875rem;
    margin-bottom: 6px;
  }
  
  .filter-row:has([data-difficulty]) .filter-group {
    gap: 6px;
  }
  
  .filter-row:has([data-difficulty]) .filter-chip {
    height: 40px;
    padding: 0 10px;
    font-size: 13px;
    border-radius: 10px;
  }
}

/* Print Styles */
@media print {
  .filters-section,
  .help-buttons,
  .question-expand-btn,
  .answer-check-btn {
    display: none;
  }

  .question-content {
    max-height: none !important;
    display: block !important;
  }

  .solution-section {
    display: block !important;
  }

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