/* GCSE Revision Hub - Content Styles */
/* Units, topics, questions, flashcards, explanations */

/* Units */
.unit {
  margin-bottom: var(--space-lg);
  border: none;
}

.unit > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-size: var(--font-lg);
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  transition: all var(--transition-fast);
}

.unit > summary::-webkit-details-marker {
  display: none;
}

.unit > summary:hover {
  border-color: var(--border-light);
  background: var(--bg-hover);
}

.unit[open] > summary {
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  border-bottom-color: transparent;
}

.unit-content {
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  padding: var(--space-md);
  background: var(--bg-primary);
}

/* Topics */
.topic {
  margin-bottom: var(--space-sm);
  border: none;
}

.topic > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-weight: 500;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  transition: all var(--transition-fast);
}

.topic > summary::-webkit-details-marker {
  display: none;
}

.topic > summary:hover {
  border-color: var(--border-light);
}

.topic[open] > summary {
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  border-bottom-color: transparent;
  background: var(--bg-hover);
}

.topic-title {
  flex: 1;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.topic-content {
  border: none;
  border-radius: 0;
  padding: var(--space-md) 0;
  background: transparent;
}

/* Content sections within topics */
.section {
  margin-bottom: var(--space-xl);
}

.section:last-child {
  margin-bottom: 0;
}

.section-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--border);
}

.section-header h3 {
  font-size: var(--font-base);
  font-weight: 600;
  color: var(--text-secondary);
}

.section-header svg {
  width: 16px;
  height: 16px;
  color: var(--accent);
}

/* Explanation content */
.explanation {
  color: var(--text-secondary);
  line-height: 1.7;
}

.explanation h4 {
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
  font-size: var(--font-base);
  color: var(--text-primary);
}

.explanation h4:first-child {
  margin-top: 0;
}

/* Key points list */
.key-points {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin-bottom: var(--space-md);
}

.key-points-title {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
  font-size: var(--font-sm);
}

.key-points ul {
  margin: 0;
  padding-left: var(--space-lg);
}

.key-points li {
  margin-bottom: var(--space-xs);
  color: var(--text-secondary);
}

/* Exam tips — styled on the parent .box-tips so the h3 heading is inside the box */
.content-box.box-tips,
.content-box.box-exam-tips {
  background: rgba(245, 158, 11, 0.05) !important;
  border: 1px solid rgba(245, 158, 11, 0.2) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
  margin-bottom: var(--space-md);
}
.exam-tips {
  /* Inner wrapper — no background needed, parent handles it */
  margin-top: var(--space-sm);
}

.exam-tips-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 600;
  color: var(--accent);
  margin-bottom: var(--space-sm);
  font-size: var(--font-sm);
}

.exam-tips ul {
  margin: 0;
  padding-left: var(--space-lg);
}

.exam-tips li {
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}

/* Questions */
.questions-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.question {
  border: none;
}

.question > summary {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  padding: var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  list-style: none;
  transition: all var(--transition-fast);
}

.question > summary::-webkit-details-marker {
  display: none;
}

.question > summary:hover {
  border-color: var(--border-light);
}

.question[open] > summary {
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  border-bottom-color: transparent;
}

.question-text {
  flex: 1;
  color: var(--text-primary);
  font-weight: 500;
}

.question-marks {
  font-size: var(--font-xs);
  color: var(--text-muted);
  background: var(--bg-hover);
  padding: 2px var(--space-sm);
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.question-answer {
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  padding: var(--space-md);
  background: var(--bg-secondary);
  color: var(--text-secondary);
}

.question-answer strong {
  color: var(--text-primary);
}

/* Flashcards section */
.flashcards-section {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--border);
}

.flashcards-section h2 {
  margin-bottom: var(--space-lg);
}

.flashcards-grid {
  display: grid;
  gap: var(--space-md);
}

.flashcard {
  border: none;
}

.flashcard > summary {
  display: block;
  padding: var(--space-md);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  list-style: none;
  font-weight: 500;
  color: var(--text-primary);
  transition: all var(--transition-fast);
}

.flashcard > summary::-webkit-details-marker {
  display: none;
}

.flashcard > summary:hover {
  border-color: var(--accent);
}

.flashcard > summary::after {
  content: "Click to reveal";
  display: block;
  font-size: var(--font-xs);
  color: var(--text-muted);
  font-weight: 400;
  margin-top: var(--space-xs);
}

.flashcard[open] > summary {
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  border-bottom-color: transparent;
}

.flashcard[open] > summary::after {
  display: none;
}

.flashcard-answer {
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  padding: var(--space-md);
  background: var(--bg-secondary);
  color: var(--text-secondary);
}

/* Cross-topic questions */
.cross-topic-section {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--border);
}

.cross-topic-section h2 {
  margin-bottom: var(--space-lg);
}

/* Equations and formulas */
.formula {
  display: inline-block;
  font-family: var(--font-mono);
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  font-size: var(--font-sm);
}

.formula-block {
  display: block;
  text-align: center;
  padding: var(--space-md);
  margin: var(--space-md) 0;
}

/* Diagrams/images */
.diagram {
  margin: var(--space-md) 0;
  text-align: center;
}

.diagram img {
  max-width: 100%;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.diagram-caption {
  margin-top: var(--space-sm);
  font-size: var(--font-sm);
  color: var(--text-muted);
  font-style: italic;
}

/* Definition lists */
.definitions {
  display: grid;
  gap: var(--space-sm);
}

.definition {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--space-md);
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--border);
}

.definition:last-child {
  border-bottom: none;
}

.definition-term {
  font-weight: 600;
  color: var(--text-primary);
}

.definition-desc {
  color: var(--text-secondary);
}

/* ==================== */
/* COLOUR-CODED CONTENT BOXES */
/* ==================== */

/* Base content box styling */
/* Content boxes — clean flat reading style */
.content-box {
  border-radius: 0;
  padding: 0 var(--space-md);
  margin: 0;
  position: relative;
  border-left: none;
  background: transparent;
}

.content-box:first-child {
  margin-top: 0;
}

/* Section headings separated by subtle dividers */
.content-box h4 {
  margin: var(--space-lg) 0 var(--space-sm);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border);
  font-size: var(--font-lg);
  font-weight: 700;
  color: var(--text-primary);
}

/* First heading — no top border */
.content-box:first-child h4 {
  border-top: none;
  margin-top: var(--space-sm);
  padding-top: 0;
}

/* Definition lists inside content boxes */
.content-box dl {
  margin: 0;
  padding: 0;
}
.content-box dt {
  font-weight: 700;
  margin-top: var(--space-md);
  padding-left: var(--space-md);
  position: relative;
}
.content-box dt::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}
.content-box dt:first-of-type {
  margin-top: 0;
}
.content-box dd {
  margin: 4px 0 0 0;
  padding-left: var(--space-md);
  line-height: 1.6;
  color: var(--text-secondary, #64748b);
}

/* Keep coloured headings for visual variety — !important overrides subject.css */
.content-box.box-story h3,
.content-box.box-story h4 {
  color: var(--color-story) !important;
}

.content-box.box-deepdive h3,
.content-box.box-deepdive h4 {
  color: var(--color-deepdive) !important;
}

.content-box.box-facts h3,
.content-box.box-facts h4 {
  color: var(--color-facts) !important;
}

.content-box.box-tips h3,
.content-box.box-tips h4 {
  color: var(--color-tips) !important;
}

/* Questions boxes */
.content-box.box-questions h3,
.content-box.box-questions h4 {
  color: var(--color-questions) !important;
}

/* Question bank: Show only 2 sample questions by default, hide rest for quizzes */
.box-questions details.question:nth-of-type(n+3) {
  display: none;
}

/* When expanded, show all questions */
.box-questions.show-all details.question {
  display: block !important;
}

/* "Show more questions" toggle */
.box-questions .questions-toggle {
  display: block;
  width: 100%;
  padding: 12px 16px;
  margin-top: 12px;
  background: var(--bg-hover);
  border: 1px dashed var(--border);
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-size: 14px;
  cursor: pointer;
  text-align: center;
  transition: all var(--transition-fast);
}

.box-questions .questions-toggle:hover {
  background: var(--bg-card);
  border-color: var(--color-questions);
  color: var(--color-questions);
}

/* Hide toggle when all questions shown */
.box-questions.show-all .questions-toggle {
  display: none;
}

/* Sample question indicator */
.box-questions details.question:nth-of-type(1)::before,
.box-questions details.question:nth-of-type(2)::before {
  content: 'Sample';
  position: absolute;
  top: 8px;
  right: 8px;
  font-size: 10px;
  padding: 2px 6px;
  background: var(--color-questions);
  color: white;
  border-radius: var(--radius-sm);
  opacity: 0.7;
}

.box-questions details.question {
  position: relative;
}

/* Equation/formula boxes - technical cyan */
.content-box.box-equation {
  text-align: center;
}

.content-box.box-equation h3,
.content-box.box-equation h4 {
  color: var(--color-equations) !important;
  text-align: left;
}

/* Diagram boxes - constrained width */
.content-box.box-diagram {
  text-align: center;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.content-box.box-diagram img {
  max-width: 100%;
  width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
  border-radius: var(--radius-md);
}

/* Diagram containers and responsive diagrams (used across subjects) */
.diagram-container {
  max-width: 800px;
  margin: var(--space-md) auto;
  text-align: center;
  box-sizing: border-box;
}

.diagram-container img,
.diagram-container svg,
img.responsive-diagram {
  max-width: 100%;
  width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
  box-sizing: border-box;
}

/* ==================== */
/* F-078: NEW CONTENT BOX TYPES */
/* ==================== */

/* Definition boxes - deep blue (key terms to memorise) */
.content-box.box-definition {
  background: rgba(30, 64, 175, 0.04) !important;
  border: 1px solid rgba(30, 64, 175, 0.15) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-definition h3,
.content-box.box-definition h4 {
  color: var(--color-definition) !important;
}

/* Definition cards — visual separation between terms */
.content-box.box-definition dl {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs, 6px);
}
.content-box.box-definition dl > div {
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  background: rgba(30, 64, 175, 0.03);
  border: 1px solid rgba(30, 64, 175, 0.08);
}
.content-box.box-definition dl > div.must-memorise {
  background: linear-gradient(135deg, rgba(239, 68, 68, 0.08), rgba(239, 68, 68, 0.15)) !important;
  border-left: 3px solid var(--error) !important;
  border-color: rgba(239, 68, 68, 0.15) !important;
  border-left-color: var(--error) !important;
}
.content-box.box-definition dl > div dt {
  margin-top: 0;
  padding-left: 0;
}
.content-box.box-definition dl > div dt::before {
  display: none;
}
.content-box.box-definition dl > div dd {
  padding-left: 0;
}

/* Mechanism boxes - teal (how/why it works) */
.content-box.box-mechanism {
  background: rgba(13, 148, 136, 0.04) !important;
  border: 1px solid rgba(13, 148, 136, 0.15) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-mechanism h3,
.content-box.box-mechanism h4 {
  color: var(--color-mechanism) !important;
}

/* Calculation boxes - purple (worked examples) */
.content-box.box-calculation {
  background: rgba(124, 58, 237, 0.04) !important;
  border: 1px solid rgba(124, 58, 237, 0.15) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-calculation h3,
.content-box.box-calculation h4 {
  color: var(--color-calculation) !important;
}

/* Misconception boxes - red (common mistakes) */
.content-box.box-misconception {
  background: rgba(220, 38, 38, 0.04) !important;
  border: 1px solid rgba(220, 38, 38, 0.15) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-misconception h3,
.content-box.box-misconception h4 {
  color: var(--color-misconception) !important;
}

/* Memory aid boxes - amber (mnemonics, visual tricks) */
.content-box.box-memory-aid {
  background: rgba(217, 119, 6, 0.04) !important;
  border: 1px solid rgba(217, 119, 6, 0.15) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-memory-aid h3,
.content-box.box-memory-aid h4 {
  color: var(--color-memory-aid) !important;
}

/* Exam focus boxes - gold (frequently examined callout) */
.content-box.box-exam-focus {
  background: rgba(202, 138, 4, 0.04) !important;
  border: 1px solid rgba(202, 138, 4, 0.15) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-exam-focus h3,
.content-box.box-exam-focus h4 {
  color: var(--color-exam-focus) !important;
}

/* Higher-only boxes - purple dashed (grade 7-9 extension) */
.content-box.box-higher-only {
  background: rgba(124, 58, 237, 0.03) !important;
  border: 1px dashed rgba(124, 58, 237, 0.3) !important;
  border-left: 3px dashed var(--color-higher) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) var(--space-md) var(--space-md) var(--space-lg) !important;
}
.content-box.box-higher-only h3,
.content-box.box-higher-only h4 {
  color: var(--color-higher) !important;
}

/* Comparison boxes - slate (side-by-side tables) */
.content-box.box-comparison {
  background: rgba(71, 85, 105, 0.03) !important;
  border: 1px solid rgba(71, 85, 105, 0.15) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-comparison h3,
.content-box.box-comparison h4 {
  color: var(--color-comparison) !important;
}
.content-box.box-comparison table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-sm) 0;
}
.content-box.box-comparison th,
.content-box.box-comparison td {
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border);
  text-align: left;
  font-size: var(--font-base);
}
.content-box.box-comparison th {
  background: var(--bg-secondary);
  font-weight: 600;
  color: var(--text-primary);
}

/* Practical — emerald green for lab/hands-on work */
.content-box.box-practical {
  background: rgba(5, 150, 105, 0.04) !important;
  border: 1px solid rgba(5, 150, 105, 0.15) !important;
  border-left: 4px solid var(--color-practical) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-practical h3,
.content-box.box-practical h4 {
  color: var(--color-practical) !important;
}

/* ==================== */
/* F-078: INLINE UTILITY CLASSES */
/* ==================== */

/* Must-memorise highlight - red accent for critical facts */
.must-memorise {
  background: linear-gradient(135deg, rgba(239, 68, 68, 0.08), rgba(239, 68, 68, 0.15));
  border-left: 3px solid var(--error);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  font-weight: 600;
  margin: var(--space-sm) 0;
}

/* Exam frequency badges */
.exam-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 10px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.3px;
  margin-left: var(--space-sm);
  white-space: nowrap;
}
.exam-badge.very-high {
  background: rgba(239, 68, 68, 0.15);
  color: #ef4444;
}
.exam-badge.high {
  background: rgba(249, 115, 22, 0.15);
  color: #f97316;
}
.exam-badge.medium {
  background: rgba(234, 179, 8, 0.15);
  color: #eab308;
}

/* Difficulty grade pills */
.grade-pill {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.3px;
  vertical-align: middle;
}
.grade-pill.higher {
  background: rgba(124, 58, 237, 0.15);
  color: #7c3aed;
}
.grade-pill.extension {
  border: 1px dashed #7c3aed;
  color: #7c3aed;
  background: transparent;
}

/* ==================== */
/* F-078: KNOWLEDGE ORGANISER */
/* ==================== */

.box-knowledge-organiser {
  border: 2px solid var(--accent);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin: var(--space-xl) 0;
  background: rgba(59, 130, 246, 0.05);
}
.box-knowledge-organiser h4 {
  color: var(--accent) !important;
  margin: 0 0 var(--space-md);
  padding-top: 0;
  border-top: none !important;
  font-size: var(--font-lg);
}
.ko-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}
.ko-section {
  padding: var(--space-md);
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
}
.ko-section h5 {
  margin: 0 0 var(--space-sm);
  color: var(--accent);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 700;
}
.ko-section ul {
  margin: 0;
  padding-left: var(--space-md);
}
.ko-section li {
  margin-bottom: 4px;
  font-size: var(--font-sm);
  line-height: 1.5;
}
/* ko-grid is always single-column for readability */
.ko-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-sm);
}
.ko-table th,
.ko-table td {
  border: 1px solid #ddd;
  padding: 4px 8px;
  text-align: center;
}
.ko-table th {
  background: var(--accent);
  color: #ffffff;
}

/* ==================== */
/* F-078: QUICK-CHECK & EXPLAIN-BACK */
/* ==================== */

.quick-check {
  background: rgba(59, 130, 246, 0.08);
  border-left: 3px solid var(--accent);
  padding: var(--space-md);
  margin: var(--space-lg) 0;
  border-radius: var(--radius-md);
}
.quick-check-question {
  margin: 0 0 var(--space-sm);
  font-size: var(--font-base);
  color: var(--text-primary);
}
.quick-check-reveal,
.explain-toggle {
  display: inline-block;
  padding: var(--space-sm) var(--space-md);
  min-height: var(--touch-target-min);
  min-width: 120px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--font-sm);
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-fast);
}
.quick-check-reveal:hover,
.explain-toggle:hover {
  background: var(--accent-hover);
}
.quick-check-answer {
  margin-top: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: rgba(34, 197, 94, 0.1);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--success);
  font-size: var(--font-base);
  color: var(--text-primary);
}
.explain-back {
  background: rgba(168, 85, 247, 0.08);
  border-left: 3px solid var(--color-story);
  padding: var(--space-md);
  margin: var(--space-lg) 0;
  border-radius: var(--radius-md);
}
.explain-prompt {
  margin: var(--space-xs) 0 var(--space-sm);
  font-style: italic;
  color: var(--text-secondary);
}
.explain-hint {
  margin-top: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: rgba(168, 85, 247, 0.1);
  border-radius: var(--radius-sm);
  font-size: var(--font-base);
  color: var(--text-primary);
}

/* ==================== */
/* SCANNABLE KEY POINTS */
/* ==================== */

.key-takeaways {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin: var(--space-md) 0;
  padding: var(--space-md);
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.takeaway {
  background: var(--accent);
  color: white;
  padding: var(--space-xs) var(--space-sm);
  border-radius: 20px;
  font-size: var(--font-xs);
  font-weight: 600;
}

/* ==================== */
/* CARD GRID FOR LISTS */
/* ==================== */

.fact-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-md);
  margin: var(--space-lg) 0;
}

.fact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  transition: all var(--transition-fast);
}

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

.fact-card-icon {
  font-size: 2em;
  margin-bottom: var(--space-sm);
}

.fact-card-title {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-xs);
}

.fact-card-desc {
  font-size: var(--font-sm);
  color: var(--text-secondary);
}

/* ==================== */
/* HIGHLIGHT KEY TERMS */
/* ==================== */

.highlight {
  background: rgba(59, 130, 246, 0.2);
  padding: 0 4px;
  border-radius: 3px;
  font-weight: 500;
}

/* Light mode highlight adjustment */
body:has(#theme-toggle:checked) .highlight {
  background: rgba(59, 130, 246, 0.15);
}

/* ==================== */
/* HISTORY-SPECIFIC INTERNAL CLASSES */
/* ==================== */

/* Cause chain — vertical causation flow (used 57+ times in history) */
.cause-chain {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin: var(--space-md) 0;
  position: relative;
}
.cause-chain::before {
  content: '';
  position: absolute;
  left: 18px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  background: var(--border);
  z-index: 0;
}
.cause-item {
  position: relative;
  padding: var(--space-sm) var(--space-md) var(--space-sm) 44px;
  margin: 4px 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--color-causation, #b45309);
  border-radius: var(--radius-sm);
  font-size: var(--font-base);
  line-height: 1.6;
  z-index: 1;
}
.cause-item::before {
  content: '→';
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 18px;
  color: var(--color-causation, #b45309);
  font-weight: bold;
}
.cause-item strong {
  color: var(--text-primary);
}

/* Turning point callout — gold accent within cause-chains */
.cause-item.turning-point {
  border-color: #ca8a04 !important;
  background: rgba(202, 138, 4, 0.06) !important;
}
.cause-item.turning-point::before {
  content: '⭐';
  font-size: 14px;
  color: #ca8a04;
}

/* Evidence list — bulleted evidence lists (65+ uses in history) */
.evidence-list {
  list-style: none;
  padding: 0;
  margin: var(--space-md) 0;
}
.evidence-list li,
div.evidence-list > li {
  position: relative;
  padding: var(--space-sm) var(--space-md) var(--space-sm) 36px;
  margin: var(--space-xs) 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--color-evidence, #166534);
  border-radius: var(--radius-sm);
  font-size: var(--font-base);
  line-height: 1.6;
}
.evidence-list li::before {
  content: '📌';
  position: absolute;
  left: 10px;
  top: var(--space-sm);
  font-size: 14px;
}
.evidence-list li strong {
  color: var(--text-primary);
}

/* Quote box — historical quotations */
.quote-box {
  margin: var(--space-lg) 0;
  padding: var(--space-lg);
  background: linear-gradient(135deg, rgba(168, 85, 247, 0.06), rgba(168, 85, 247, 0.02));
  border-left: 4px solid var(--color-story);
  border-radius: var(--radius-md);
  position: relative;
}
.quote-box::before {
  content: '"';
  position: absolute;
  top: 8px;
  left: 12px;
  font-size: 48px;
  color: var(--color-story);
  opacity: 0.3;
  font-family: Georgia, serif;
  line-height: 1;
}
.quote-text {
  font-size: var(--font-lg);
  font-style: italic;
  color: var(--text-primary);
  line-height: 1.6;
  padding-left: 24px;
  margin-bottom: var(--space-sm);
}
.quote-source {
  font-size: var(--font-sm);
  color: var(--text-secondary);
  padding-left: 24px;
  font-weight: 600;
}

/* Stats table — evidence data tables */
.stats-table,
.styled-table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-md) 0;
  font-size: var(--font-base);
}
.stats-table th,
.styled-table th {
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-weight: 700;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border);
  text-align: left;
  font-size: var(--font-sm);
  text-transform: uppercase;
  letter-spacing: 0.3px;
}
.stats-table td,
.styled-table td {
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border);
  text-align: left;
  font-size: var(--font-base);
  line-height: 1.5;
}
.stats-table tr:nth-child(even),
.styled-table tr:nth-child(even) {
  background: rgba(0, 0, 0, 0.02);
}

/* Story hook — engaging opening text in box-story */
.story-hook {
  font-size: var(--font-base);
  line-height: 1.7;
  color: var(--text-primary);
  font-style: italic;
  padding: var(--space-sm) 0;
}

/* Video link styling */
.video-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  text-decoration: none;
  font-size: var(--font-sm);
  font-weight: 500;
  transition: all var(--transition-fast);
}
.video-link:hover {
  background: rgba(239, 68, 68, 0.15);
  border-color: rgba(239, 68, 68, 0.4);
}
.video-link-content {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}
.video-play-icon {
  color: #ef4444;
  font-size: 16px;
}

/* ==================== */
/* HISTORY-SPECIFIC BOX TYPES */
/* ==================== */

/* Causation boxes — amber/brown (why things happened, chains of cause & consequence) */
.content-box.box-causation {
  background: rgba(180, 83, 9, 0.04) !important;
  border: 1px solid rgba(180, 83, 9, 0.15) !important;
  border-left: 4px solid var(--color-causation) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-causation h3,
.content-box.box-causation h4 {
  color: var(--color-causation) !important;
}

/* Significance boxes — purple (why events matter, their lasting impact) */
.content-box.box-significance {
  background: rgba(126, 34, 206, 0.04) !important;
  border: 1px solid rgba(126, 34, 206, 0.15) !important;
  border-left: 4px solid var(--color-significance) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-significance h3,
.content-box.box-significance h4 {
  color: var(--color-significance) !important;
}

/* Interpretation boxes — ocean blue (how and why historians disagree) */
.content-box.box-interpretation {
  background: rgba(3, 105, 161, 0.04) !important;
  border: 1px solid rgba(3, 105, 161, 0.15) !important;
  border-left: 4px solid var(--color-interpretation) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-interpretation h3,
.content-box.box-interpretation h4 {
  color: var(--color-interpretation) !important;
}

/* Source analysis boxes — crimson (how to use primary sources as evidence) */
.content-box.box-source-analysis {
  background: rgba(159, 18, 57, 0.04) !important;
  border: 1px solid rgba(159, 18, 57, 0.15) !important;
  border-left: 4px solid var(--color-source-analysis) !important;
  border-radius: var(--radius-md) !important;
  padding: var(--space-md) !important;
}
.content-box.box-source-analysis h3,
.content-box.box-source-analysis h4 {
  color: var(--color-source-analysis) !important;
}

/* ==================== */
/* RESPONSIVE ADJUSTMENTS */
/* ==================== */

@media (max-width: 600px) {
  .unit > summary {
    padding: var(--space-sm) var(--space-md);
    font-size: var(--font-base);
  }

  .topic > summary {
    padding: var(--space-sm);
  }

  .topic-content {
    padding: var(--space-md);
  }

  .definition {
    grid-template-columns: 1fr;
    gap: var(--space-xs);
  }

  .content-box {
    padding: var(--space-md);
    margin: var(--space-lg) 0;
  }

  .fact-cards {
    grid-template-columns: 1fr;
  }

  /* History internal classes mobile adjustments */
  .cause-chain::before {
    left: 14px;
  }
  .cause-item {
    padding-left: 36px;
    font-size: var(--font-sm);
  }
  .cause-item::before {
    left: 8px;
    font-size: 14px;
  }
  .evidence-list li {
    padding-left: 30px;
    font-size: var(--font-sm);
  }
  .quote-box {
    padding: var(--space-md);
  }
  .quote-text {
    font-size: var(--font-base);
    padding-left: 16px;
  }
  .quote-source {
    padding-left: 16px;
  }
}