/* css/components/exercise.css */
/* Main exercise layout and container styles */

.exercise-container {
  background: white;
  border-radius: 20px;
  padding: 30px;
  box-shadow: var(--shadow-lg);
  margin-bottom: 40px;
  border: 1px solid var(--border-light);
}

.exercise-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
  gap: 16px;
}

.exercise-title h2 {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 6px;
}

.exercise-subtitle {
  font-size: 1rem;
  color: var(--text-light);
  margin-bottom: 8px;
}

.exercise-badge {
  display: inline-block;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  padding: 4px 14px;
  border-radius: 30px;
  font-size: 0.95rem;
  font-weight: 600;
}

.exercise-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.btn-exit {
  background: #f1f5f9;
  border: none;
  color: var(--text-medium);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.1rem;
  transition: all 0.2s;
}

.btn-exit:hover {
  background: #fee2e2;
  color: var(--incorrect);
  transform: rotate(90deg);
}

/* Cambridge Score buttons in exercise toolbar */
.btn-cambridge-score {
  background: #e30613;
  border: none;
  color: #fff;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1rem;
  transition: all 0.2s;
  box-shadow: 0 2px 8px rgba(227, 6, 19, 0.3);
}

.btn-cambridge-score:hover {
  background: #c00510;
  transform: scale(1.1);
  box-shadow: 0 4px 12px rgba(227, 6, 19, 0.45);
}

.btn-cambridge-overall {
  background: #b71c1c;
  box-shadow: 0 2px 8px rgba(183, 28, 28, 0.3);
}

.btn-cambridge-overall:hover {
  background: #8e0000;
  box-shadow: 0 4px 12px rgba(183, 28, 28, 0.45);
}

.exercise-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-light);
  border-radius: 16px;
  padding: 12px 20px;
  margin-bottom: 20px;
  gap: 12px;
  flex-wrap: wrap;
}

.exercise-info-left {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 1.05rem;
  color: var(--text-medium);
  font-weight: 500;
}

.exercise-info-left i {
  margin-right: 6px;
  color: var(--primary);
}

.exercise-info-right {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.exercise-duration {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  white-space: nowrap;
  flex-shrink: 0;
  font-weight: 600;
  color: var(--text-medium);
}

.exercise-duration i {
  color: var(--primary);
}

.exercise-timer {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--timer-normal);
}

.exercise-timer i {
  color: var(--primary);
}

.score-display {
  background: var(--primary);
  color: white;
  padding: 6px 16px;
  border-radius: 30px;
  font-weight: 700;
  font-size: 1.05rem;
  min-width: 60px;
  text-align: center;
}

.exercise-description {
  background: linear-gradient(135deg, #f0f4ff, #f8fafc);
  border-left: 4px solid var(--primary);
  padding: 10px 16px;
  border-radius: 8px;
  margin-bottom: 24px;
  font-size: 1.05rem;
  color: var(--text-medium);
  line-height: 1.5;
}

.exercise-main-layout {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 20px;
}

.reading-text-enhanced {
  font-size: 1.15rem;
  line-height: 1.9;
  color: var(--text-dark);
  background: #fafcff;
  padding: 28px;
  border-radius: 20px;
  border: 1px solid var(--border-light);
  position: relative;
  text-align: justify;
}

.reading-text-enhanced p {
  margin-bottom: 16px;
}

.reading-text-enhanced p:last-child {
  margin-bottom: 0;
}

.explanations-section {
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 20px;
  padding: 24px;
  margin-top: 24px;
}

.explanations-section h3 {
  color: var(--text-dark);
  font-size: 1.2rem;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.explanation-item {
  padding: 12px 16px;
  background: white;
  border-radius: 10px;
  margin-bottom: 10px;
  font-size: 1.05rem;
  color: var(--text-medium);
  border-left: 3px solid #f59e0b;
  line-height: 1.6;
}

.explanation-item strong {
  color: var(--text-dark);
}

/* Toggle view for text/questions (Parts 5, 6, 8) */
.toggle-view-header {
  display: flex;
  justify-content: flex-start;
  gap: 8px;
  margin-bottom: 16px;
}

.toggle-view-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  border: 2px solid #e2e8f0;
  border-radius: 30px;
  background: #f8fafc;
  color: var(--text-medium);
  font-family: 'Nunito', sans-serif;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.2s;
}

.toggle-view-btn:hover {
  border-color: var(--primary-light);
  background: #f0f4ff;
  color: var(--primary);
}

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

.toggle-view-btn.active:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
  color: white;
}

/* Part-level progress pill */
.part-score-display {
  background: var(--secondary);
  color: white;
  padding: 4px 14px;
  border-radius: 30px;
  font-weight: 700;
  font-size: 0.95rem;
  min-width: 50px;
  text-align: center;
}

/* Content section header with title/subtitle and toggle buttons */
.content-section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #f8fafc;
  border-radius: 16px;
  padding: 14px 20px;
  margin-bottom: 16px;
  margin-top: 16px;
  gap: 12px;
}

.content-title-block {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.content-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-dark);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.content-subtitle {
  font-size: 0.95rem;
  color: var(--text-light);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.content-section-header .toggle-view-header {
  margin-bottom: 0;
  flex-shrink: 0;
}

/* Exercise header right section */
.exercise-header-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

/* Part navigation row */
.part-nav-row {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.part-nav-cell {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  border: 2px solid #e2e8f0;
  background: #f8fafc;
  color: var(--text-medium);
  font-weight: 700;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.2s;
  font-family: 'Nunito', sans-serif;
}

.part-nav-cell:hover {
  border-color: var(--primary-light);
  background: #f0f4ff;
  color: var(--primary);
}

.part-nav-cell.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.part-nav-cell.completed {
  background: #dcfce7;
  border-color: #86efac;
  color: #16a34a;
}

.part-nav-cell.completed.active {
  background: #16a34a;
  color: white;
  border-color: #16a34a;
}

.part-nav-check {
  position: absolute;
  top: -4px;
  right: -4px;
  font-size: 0.55rem;
  background: #16a34a;
  color: white;
  border-radius: 50%;
  width: 14px;
  height: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ============================================
   EXERCISE ERROR CARD
   ============================================ */
.exercise-error-card {
  background: linear-gradient(135deg, #fff1f2 0%, #ffffff 100%);
  border: 1.5px solid #fecaca;
  border-radius: 20px;
  padding: 48px 40px;
  text-align: center;
  max-width: 520px;
  margin: 40px auto;
  box-shadow: 0 4px 24px rgba(239, 68, 68, 0.08);
  animation: fadeInUp 0.4s ease;
}

.exercise-error-icon {
  width: 72px;
  height: 72px;
  background: linear-gradient(135deg, #ef4444, #dc2626);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  box-shadow: 0 4px 16px rgba(239, 68, 68, 0.3);
}

.exercise-error-icon i {
  font-size: 2rem;
  color: white;
}

.exercise-error-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: #991b1b;
  margin-bottom: 10px;
}

.exercise-error-desc {
  color: #6b7280;
  font-size: 1rem;
  margin-bottom: 16px;
}

.exercise-error-detail {
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: 10px;
  padding: 10px 16px;
  margin-bottom: 24px;
}

.exercise-error-detail code {
  font-size: 0.85rem;
  color: #b91c1c;
  word-break: break-word;
}

.exercise-error-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.exercise-error-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: 12px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: 'Nunito', sans-serif;
  cursor: pointer;
  border: none;
  transition: all 0.2s;
}

.exercise-error-btn-primary {
  background: linear-gradient(135deg, var(--primary), #2563eb);
  color: white;
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3);
}

.exercise-error-btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(59, 130, 246, 0.4);
}

.exercise-error-btn-secondary {
  background: #f3f4f6;
  color: #374151;
  border: 1px solid #e5e7eb;
}

.exercise-error-btn-secondary:hover {
  background: #e5e7eb;
  transform: translateY(-1px);
}

/* ====== Explanation mode styles ====== */

/* Explanation button in toggle-view-header */
.toggle-view-btn.btn-explanation-mode {
  border-color: #f97316;
  color: #f97316;
}

.toggle-view-btn.btn-explanation-mode:hover {
  background: #fff7ed;
  border-color: #ea580c;
  color: #ea580c;
}

.toggle-view-btn.btn-explanation-mode.explanation-active {
  background: #f97316;
  border-color: #f97316;
  color: #fff;
}

.toggle-view-btn.btn-explanation-mode.explanation-active:hover {
  background: #ea580c;
  border-color: #ea580c;
  color: #fff;
}

/* Active question display above text */
.explanation-question-display {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: #fff7ed;
  border: 2px solid #f97316;
  border-radius: 12px;
  padding: 12px 18px;
  margin-bottom: 12px;
  font-size: 1rem;
  line-height: 1.5;
  color: var(--text-dark);
  position: static;
  z-index: 10;
}

.explanation-question-display.sticky-mode {
  position: sticky;
  top: 0;
}

.eq-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: #f97316;
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  min-width: 30px;
  min-height: 30px;
  aspect-ratio: 1;
  border-radius: 50%;
  flex-shrink: 0;
  padding: 0;
}

.eq-text {
  font-weight: 500;
  color: #7c2d12;
}

.eq-question-text {
  font-weight: 600;
  color: var(--text-dark);
  font-size: 0.95rem;
  line-height: 1.5;
}

/* Options layout: rows for Part 5 */
.eq-options.eq-options-rows {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-top: 4px;
}

/* Options layout: columns for Parts 6, 8 */
.eq-options.eq-options-columns {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 4px;
}

/* Evidence markers in text (rendered from [n]...[/n]) */
.evidence-marker {
  transition: background 0.2s, border-bottom 0.2s;
}

.evidence-marker.evidence-active {
  background: #fed7aa;
  border-bottom: 2px solid #f97316;
  border-radius: 3px;
  padding: 0 1px;
  position: relative;
  cursor: help;
}

.evidence-marker.evidence-active[data-explanation]::after {
  content: attr(data-explanation);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  background: #1a3a5c;
  color: white;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 0.8rem;
  white-space: normal;
  max-width: 300px;
  min-width: 150px;
  display: none;
  z-index: 30;
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
  font-weight: 500;
  line-height: 1.4;
  pointer-events: none;
}

.evidence-marker.evidence-active[data-explanation]:hover::after {
  display: block;
}

/* Options display in explanation-question-display */
.eq-content {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}

.eq-options {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 4px;
}

.eq-option {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.88rem;
  background: #f1f5f9;
  color: var(--text-medium);
  border: 1px solid #e2e8f0;
}

.eq-option.eq-option-correct {
  background: #fff7ed;
  color: #ea580c;
  border-color: #f97316;
  font-weight: 600;
}

/* Explanations panel below exercise (Parts 5-8) */
.explanations-panel {
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 20px;
  padding: 24px;
  margin-top: 24px;
}

.explanations-panel h3 {
  color: var(--text-dark);
  font-size: 1.2rem;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.explanation-card {
  padding: 16px;
  background: white;
  border-radius: 12px;
  margin-bottom: 12px;
  border-left: 4px solid #e2e8f0;
  cursor: pointer;
  transition: all 0.2s;
}

.explanation-card:hover {
  border-left-color: #f97316;
  box-shadow: 0 2px 8px rgba(249, 115, 22, 0.1);
}

.explanation-card.explanation-active {
  border-left-color: #f97316;
  background: #fff7ed;
  box-shadow: 0 2px 12px rgba(249, 115, 22, 0.15);
}

.explanation-card-header {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.explanation-card-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: #f97316;
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  min-width: 28px;
  height: 28px;
  border-radius: 50%;
  flex-shrink: 0;
  padding: 0 4px;
}

.explanation-card-text {
  font-size: 0.95rem;
  color: var(--text-medium);
  line-height: 1.6;
  flex: 1;
}

/* Listening transcript in main content area */
.listening-transcript-main {
  padding: 0;
}

.listening-transcript-main .transcript-extract {
  margin-bottom: 16px;
}

.listening-transcript-main .transcript-text {
  font-size: 1rem;
  line-height: 1.8;
  text-align: justify;
}

@media (max-width: 768px), (max-height: 520px) and (orientation: landscape) and (max-width: 1024px) {
  .exercise-container {
    border-radius: 18px;
    padding: 18px;
    margin-bottom: 24px;
  }

  .exercise-header {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .exercise-title h2 {
    font-size: 1.28rem;
    overflow-wrap: anywhere;
  }

  .exercise-toolbar,
  .exercise-header-right {
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .exercise-info,
  .exercise-info-left,
  .exercise-info-right {
    align-items: stretch;
    flex-direction: column;
    gap: 10px;
  }

  .exercise-info {
    padding: 12px 14px;
  }

  .score-display,
  .part-score-display {
    align-self: flex-start;
  }

  .reading-text-enhanced,
  .listening-transcript-main .transcript-text {
    text-align: left;
  }

  .reading-text-enhanced {
    padding: 18px;
    font-size: 1.02rem;
    line-height: 1.75;
  }

  .content-section-header {
    flex-direction: column;
    align-items: stretch;
    padding: 12px 14px;
  }

  .content-title,
  .content-subtitle {
    white-space: normal;
    overflow-wrap: anywhere;
  }

  .content-section-header .toggle-view-header,
  .toggle-view-header {
    overflow-x: auto;
    padding-bottom: 4px;
    -webkit-overflow-scrolling: touch;
  }

  .toggle-view-btn {
    flex: 0 0 auto;
  }

  .part-nav-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(44px, 1fr));
  }

  .part-nav-cell {
    width: auto;
    min-height: 44px;
  }
}

@media (max-width: 420px) {
  .exercise-container {
    padding: 14px;
    border-radius: 16px;
  }

  .exercise-description,
  .reading-text-enhanced,
  .explanations-section {
    padding: 14px;
  }
}

@media (max-width: 768px), (max-height: 520px) and (orientation: landscape) and (max-width: 1024px) {
  .exercise-container {
    position: relative;
    padding: 14px;
  }

  .exercise-header {
    margin-bottom: 10px;
    padding-right: 46px;
  }

  .exercise-title h2 {
    margin-bottom: 2px;
    font-size: 1.08rem;
    line-height: 1.15;
  }

  .exercise-subtitle,
  .exercise-badge,
  .mixed-mode-badge,
  .exam-mode-badge {
    font-size: 0.72rem;
  }

  .exercise-header-right {
    gap: 8px;
  }

  .btn-exit {
    position: absolute;
    top: 10px;
    right: 10px;
    width: 36px;
    height: 36px;
    min-height: 36px !important;
    z-index: 3;
  }

  .btn-cambridge-score {
    width: 34px;
    height: 34px;
    min-height: 34px !important;
  }

  .score-display {
    min-width: 48px;
    padding: 5px 10px;
    font-size: 0.86rem;
  }

  .exercise-info {
    display: grid;
    grid-template-columns: 1fr;
    gap: 7px;
    padding: 8px 10px;
    margin-bottom: 10px;
    border-radius: 14px;
  }

  .exercise-info-left,
  .exercise-info-right {
    min-width: 0;
    flex-direction: row;
    align-items: center;
    gap: 8px;
    font-size: 0.82rem;
  }

  .exercise-info-left {
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
  }

  .exercise-info-right {
    justify-content: flex-start;
    flex-wrap: wrap;
    row-gap: 6px;
  }

  .toggle-view-btn {
    width: 42px;
    height: 42px;
    min-height: 42px !important;
    padding: 0;
    border-radius: 14px;
    gap: 0;
    justify-content: center;
    align-items: center;
  }

  .toggle-view-btn span {
    display: none;
  }

  .toggle-view-btn i {
    margin: 0;
    font-size: 1rem;
    line-height: 1;
  }

  .part-nav-row {
    display: flex;
    flex-wrap: nowrap;
    gap: 5px;
  }

  .part-nav-cell {
    flex: 0 0 32px;
    width: 32px;
    height: 32px;
    min-height: 32px !important;
    border-radius: 9px;
    font-size: 0.86rem;
  }

  .exercise-timer,
  .part-score-display {
    font-size: 0.84rem;
  }

  .part-score-display {
    min-width: 44px;
    padding: 4px 9px;
  }

  .exercise-description {
    margin-bottom: 12px;
    padding: 8px 10px;
    font-size: 0.86rem;
    line-height: 1.45;
    overflow: visible;
    display: block;
    -webkit-line-clamp: unset;
    -webkit-box-orient: unset;
  }

  .exercise-description p {
    margin: 0;
  }

  .exercise-main-layout {
    gap: 12px;
    margin-top: 10px;
  }

  .reading-text-enhanced {
    padding: 14px;
    border-radius: 16px;
    font-size: 0.96rem;
    line-height: 1.65;
  }

  .content-section-header {
    gap: 8px;
    margin: 10px 0;
  }

  .explanations-section,
  .explanations-panel {
    padding: 14px;
    border-radius: 16px;
  }
}