/* ============================================================
   jee-sm.css  —  IIT JEE Study Material pages
   Two-level tab system: L1 = topic pills, L2 = content tabs
   Page never scrolls; only .content-panel scrolls internally.
   ============================================================ */

/* ── Layout shell ── */
/* Fixed shell below the topbar; on desktop, inset from the left so the
   persistent sidebar (z-index 400) doesn't paint over content. */
.jee-sm-main {
  position: fixed;
  top: var(--topbar-height);
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg);
  z-index: 10;
}

@media (min-width: 1024px) {
  body:has(.sidebar) .jee-sm-main {
    left: var(--sidebar-width, 240px);
  }
  body.sidebar-collapsed .jee-sm-main {
    left: var(--sidebar-collapsed, 60px);
  }
}

/* Active topic panel fills remaining vertical space */
.topic-panel:not([hidden]) {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-height: 0;
}

/* ── Mastery strip (top progress bar) ── */
.mastery-strip {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 20px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-secondary);
  flex-shrink: 0;
  flex-wrap: wrap;
}

.mastery-strip__title {
  font-weight: 600;
  color: var(--text);
  font-size: 0.8rem;
  margin-right: 4px;
}

.mastery-strip__streak {
  display: flex;
  align-items: center;
  gap: 4px;
  font-weight: 700;
  color: #f57c00;
  background: #fff3e0;
  border-radius: 20px;
  padding: 2px 10px;
  font-size: 0.75rem;
}

[data-theme="dark"] .mastery-strip__streak {
  background: rgba(245, 124, 0, 0.15);
}

.mastery-strip__bar-wrap {
  flex: 1;
  min-width: 80px;
  max-width: 200px;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}

.mastery-strip__bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--clr-success), #81c784);
  border-radius: 3px;
  transition: width 0.5s ease;
}

.mastery-strip__count {
  font-weight: 600;
  color: var(--clr-success);
  white-space: nowrap;
}

.mastery-strip__cotd {
  margin-left: auto;
  font-style: italic;
  color: var(--text-secondary);
  font-size: 0.7rem;
  max-width: 300px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

@media (max-width: 600px) {
  .mastery-strip { padding: 6px 12px; gap: 8px; }
  .mastery-strip__cotd { display: none; }
}

/* ── L1: Topic tab row ── */
.topic-tab-row {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  overflow-x: auto;
  flex-shrink: 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  scroll-snap-type: x mandatory;
  -ms-overflow-style: none;
  scrollbar-width: none;
}

.topic-tab-row::-webkit-scrollbar { display: none; }

.topic-tab-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 20px;
  border: 1.5px solid var(--border);
  background: var(--bg);
  color: var(--text-secondary);
  font-size: 0.78rem;
  font-weight: 500;
  white-space: nowrap;
  cursor: pointer;
  scroll-snap-align: start;
  transition: background var(--dur-fast), color var(--dur-fast), border-color var(--dur-fast);
  position: relative;
  flex-shrink: 0;
}

.topic-tab-pill:hover {
  background: var(--surface-hover);
  border-color: var(--content-accent);
  color: var(--text);
}

.topic-tab-pill.active {
  background: var(--content-accent);
  border-color: var(--content-accent);
  color: #fff;
  font-weight: 600;
}

/* mastery state dots */
.topic-tab-pill::after {
  content: '';
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--border);
  flex-shrink: 0;
}

.topic-tab-pill.visited::after   { background: #ffd54f; }
.topic-tab-pill.read::after      { background: #4fc3f7; }
.topic-tab-pill.mastered::after  { background: #66bb6a; }
.topic-tab-pill.due::after       { background: #ff7043; }

.topic-tab-pill.active::after    { background: rgba(255,255,255,0.7); }

/* spaced-repetition badge */
.topic-tab-pill[data-due="true"] .due-badge {
  display: inline-block;
}
.due-badge {
  display: none;
  font-size: 0.6rem;
  background: #ff7043;
  color: #fff;
  border-radius: 3px;
  padding: 0 4px;
  line-height: 1.5;
  font-weight: 700;
}

/* ── L2: Content tab bar ── */
.content-tab-bar {
  display: flex;
  align-items: stretch;
  border-bottom: 2px solid var(--border);
  background: var(--bg);
  flex-shrink: 0;
  padding: 0 20px;
}

.content-tab-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  border: none;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  background: none;
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: color var(--dur-fast), border-color var(--dur-fast);
  white-space: nowrap;
  font-family: 'Poppins', sans-serif;
}

.content-tab-btn:hover { color: var(--text); }

.content-tab-btn.active {
  color: var(--content-accent);
  border-bottom-color: var(--content-accent);
  font-weight: 600;
}

.content-tab-btn .ctab-icon { font-size: 1rem; }
.content-tab-btn .ctab-label { }

@media (max-width: 520px) {
  .content-tab-bar { padding: 0 8px; }
  .content-tab-btn { padding: 10px 10px; font-size: 0.75rem; gap: 4px; }
  .content-tab-btn .ctab-label { display: none; }
  .content-tab-btn .ctab-icon  { font-size: 1.1rem; }
}

/* ── Content panel (the only scrollable area) ── */
.content-panel-wrap {
  flex: 1;
  overflow: hidden;
  position: relative;
}

.content-panel {
  height: 100%;
  overflow-y: auto;
  padding: 24px 28px;
  display: none;
}

.content-panel.active { display: block; }

@media (max-width: 600px) {
  .content-panel { padding: 16px 14px; }
}

/* ── Sticky footer bar ── */
.sticky-footer-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 10px 20px;
  border-top: 1px solid var(--border);
  background: var(--bg);
  flex-shrink: 0;
}

.sfb-nav-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border);
  background: var(--bg);
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--dur-fast), color var(--dur-fast), border-color var(--dur-fast);
  font-family: 'Poppins', sans-serif;
}

.sfb-nav-btn:hover:not(:disabled) {
  background: var(--surface-hover);
  border-color: var(--content-accent);
  color: var(--text);
}

.sfb-nav-btn:disabled { opacity: 0.35; cursor: default; }

.sfb-center {
  display: flex;
  align-items: center;
  gap: 8px;
}

.sfb-mark-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 16px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--clr-success);
  background: var(--bg);
  color: var(--clr-success);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--dur-fast), color var(--dur-fast);
  font-family: 'Poppins', sans-serif;
}

.sfb-mark-btn:hover { background: var(--clr-success); color: #fff; }
.sfb-mark-btn.marked { background: var(--clr-success); color: #fff; cursor: default; }

.sfb-test-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 16px;
  border-radius: var(--radius-sm);
  border: none;
  background: var(--content-accent);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: opacity var(--dur-fast);
  font-family: 'Poppins', sans-serif;
}

.sfb-test-btn:hover { opacity: 0.87; }

@media (max-width: 500px) {
  .sticky-footer-bar { padding: 8px 10px; }
  .sfb-nav-btn .sfb-label { display: none; }
  .sfb-test-btn .sfb-label { display: none; }
}

/* ── Module completion banner ── */
.module-complete-banner {
  display: none;
  align-items: center;
  gap: 12px;
  padding: 12px 20px;
  background: linear-gradient(135deg, #e8f5e9, #f1f8e9);
  border-top: 2px solid #66bb6a;
  color: #2e7d32;
  font-size: 0.85rem;
  font-weight: 600;
  flex-shrink: 0;
}

[data-theme="dark"] .module-complete-banner {
  background: rgba(102, 187, 106, 0.12);
  border-top-color: #66bb6a;
  color: #81c784;
}

.module-complete-banner.visible { display: flex; }

.module-complete-banner a {
  margin-left: auto;
  padding: 5px 14px;
  background: #43a047;
  color: #fff;
  border-radius: 20px;
  text-decoration: none;
  font-size: 0.78rem;
  white-space: nowrap;
}

/* ═══════════════════════════════════════════
   CONTENT PANEL COMPONENTS
═══════════════════════════════════════════ */

/* ── Theory tab ── */
.theory-section { margin-bottom: 28px; }

.theory-section h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--content-primary);
  margin: 0 0 10px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--divider-light);
}

.theory-section p {
  font-size: 0.88rem;
  line-height: 1.7;
  color: var(--text);
  margin: 0 0 10px;
}

.theory-section ul,
.theory-section ol {
  font-size: 0.88rem;
  line-height: 1.7;
  color: var(--text);
  padding-left: 20px;
  margin: 0 0 10px;
}

.theory-section li { margin-bottom: 4px; }

.theory-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
  margin: 10px 0 18px;
}

.theory-table th {
  background: var(--surface-alt);
  color: var(--content-primary);
  font-weight: 600;
  padding: 8px 12px;
  text-align: left;
  border: 1px solid var(--divider-light);
}

.theory-table td {
  padding: 7px 12px;
  border: 1px solid var(--divider-light);
  vertical-align: top;
  color: var(--text);
}

.theory-table tr:nth-child(even) td { background: var(--surface-stripe); }

/* ── JEE tip callout ── */
.jee-tip-box {
  display: flex;
  gap: 10px;
  padding: 12px 16px;
  background: #dbeafe;
  border-left: 4px solid #3b82f6;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 14px 0;
  font-size: 0.83rem;
  line-height: 1.6;
  color: #1e40af;
}

[data-theme="dark"] .jee-tip-box {
  background: rgba(37, 99, 235, 0.12);
  color: #63b3ed;
  border-left-color: #42a5f5;
}

.jee-tip-box .tip-icon { font-size: 1rem; flex-shrink: 0; margin-top: 1px; }

.jee-warning-box {
  display: flex;
  gap: 10px;
  padding: 12px 16px;
  background: #fff8e1;
  border-left: 4px solid #f9a825;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 14px 0;
  font-size: 0.83rem;
  line-height: 1.6;
  color: #6d4c00;
}

[data-theme="dark"] .jee-warning-box {
  background: rgba(249, 168, 37, 0.12);
  color: #ffe082;
  border-left-color: #ffa000;
}

/* ── Formulas tab ── */
.formula-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

@media (max-width: 640px) {
  .formula-grid { grid-template-columns: 1fr; }
}

.formula-card {
  background: var(--card-bg);
  border: 1px solid var(--divider-light);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  position: relative;
  transition: box-shadow var(--dur-fast);
}

.formula-card:hover { box-shadow: var(--shadow-md); }

.formula-card__name {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.formula-card__expr {
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.97rem;
  font-weight: 600;
  color: var(--content-primary);
  margin-bottom: 6px;
  word-break: break-word;
}

[data-theme="dark"] .formula-card__expr { color: #63b3ed; }

.formula-card__note {
  font-size: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.formula-card__unit {
  position: absolute;
  top: 10px;
  right: 12px;
  font-size: 0.68rem;
  background: var(--surface-alt);
  color: var(--text-secondary);
  padding: 2px 6px;
  border-radius: 4px;
  font-weight: 600;
}

.formula-group-label {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--content-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 20px 0 10px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--divider-light);
}

/* copy button */
.formula-card__copy {
  position: absolute;
  bottom: 10px;
  right: 10px;
  background: none;
  border: none;
  cursor: pointer;
  opacity: 0;
  font-size: 0.75rem;
  color: var(--content-accent);
  transition: opacity var(--dur-fast);
  padding: 2px 6px;
}

.formula-card:hover .formula-card__copy { opacity: 1; }
.formula-card__copy.copied { opacity: 1; color: var(--clr-success); }

/* ── Examples tab ── */
.solved-example {
  background: var(--card-bg);
  border: 1px solid var(--divider-light);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  overflow: hidden;
}

.solved-example__header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: var(--surface-alt);
  border-bottom: 1px solid var(--divider-light);
}

.solved-example__num {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.difficulty-badge {
  font-size: 0.68rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.difficulty-badge.easy   { background: #e8f5e9; color: #2e7d32; }
.difficulty-badge.medium { background: #fff8e1; color: #6d4c00; }
.difficulty-badge.hard   { background: #fce4ec; color: #880e4f; }

[data-theme="dark"] .difficulty-badge.easy   { background: rgba(46,125,50,0.18); color: #81c784; }
[data-theme="dark"] .difficulty-badge.medium { background: rgba(109,76,0,0.18); color: #ffe082; }
[data-theme="dark"] .difficulty-badge.hard   { background: rgba(136,14,79,0.18); color: #f48fb1; }

.solved-example__source {
  margin-left: auto;
  font-size: 0.68rem;
  color: var(--text-secondary);
  font-style: italic;
}

.solved-example__title {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text);
}

.solved-example__body { padding: 14px 16px; }

.solved-example__q {
  font-size: 0.87rem;
  line-height: 1.7;
  color: var(--text);
  margin-bottom: 12px;
}

.solved-example__hint {
  margin-bottom: 12px;
}

.solved-example__hint summary {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--content-accent);
  cursor: pointer;
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 6px;
}

.solved-example__hint summary::before { content: '💡'; }
.solved-example__hint summary::-webkit-details-marker { display: none; }

.solved-example__hint[open] summary::before { content: '💡'; }

.solved-example__hint-body {
  margin-top: 8px;
  padding: 10px 14px;
  background: #f0f4fb;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

[data-theme="dark"] .solved-example__hint-body { background: rgba(74,144,226,0.08); }

.solved-example__steps {
  counter-reset: step-counter;
  list-style: none;
  padding: 0;
  margin: 0 0 14px;
}

.solved-example__steps li {
  counter-increment: step-counter;
  display: flex;
  gap: 10px;
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--text);
  margin-bottom: 8px;
  padding-left: 0;
}

.solved-example__steps li::before {
  content: counter(step-counter);
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--content-accent);
  color: #fff;
  font-size: 0.68rem;
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 3px;
}

.solved-example__answer {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  background: #e8f5e9;
  border-radius: var(--radius-sm);
  font-size: 0.87rem;
  font-weight: 700;
  color: #1b5e20;
}

[data-theme="dark"] .solved-example__answer {
  background: rgba(46, 125, 50, 0.15);
  color: #a5d6a7;
}

/* ── Diagrams tab ── */
.diagram-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.diagram-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.svg-frame {
  background: var(--card-bg);
  border: 1px solid var(--divider-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  cursor: zoom-in;
  transition: box-shadow var(--dur-fast);
}

.svg-frame:hover { box-shadow: var(--shadow-md); }

.svg-frame svg {
  width: 100%;
  height: auto;
  display: block;
}

.svg-frame__caption {
  padding: 8px 12px;
  font-size: 0.75rem;
  color: var(--text-secondary);
  border-top: 1px solid var(--divider-light);
  line-height: 1.4;
}

/* zoom overlay */
.svg-zoom-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.82);
  z-index: 9000;
  align-items: center;
  justify-content: center;
  cursor: zoom-out;
}

.svg-zoom-overlay.open { display: flex; }

.svg-zoom-overlay svg {
  max-width: 90vw;
  max-height: 85vh;
  background: #fff;
  border-radius: var(--radius-md);
  padding: 20px;
}

/* ── Quick Quiz tab ── */
.quiz-question {
  background: var(--card-bg);
  border: 1px solid var(--divider-light);
  border-radius: var(--radius-md);
  padding: 16px;
  margin-bottom: 16px;
}

.quiz-question__num {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.quiz-question__text {
  font-size: 0.88rem;
  line-height: 1.7;
  color: var(--text);
  margin-bottom: 12px;
}

.quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

@media (max-width: 500px) {
  .quiz-options { grid-template-columns: 1fr; }
}

.quiz-option-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 0.83rem;
  cursor: pointer;
  text-align: left;
  transition: background var(--dur-fast), border-color var(--dur-fast), color var(--dur-fast);
  font-family: 'Poppins', sans-serif;
}

.quiz-option-btn:hover:not(:disabled) {
  background: var(--surface-hover);
  border-color: var(--content-accent);
}

.quiz-option-btn .opt-letter {
  font-weight: 700;
  color: var(--content-accent);
  flex-shrink: 0;
  min-width: 16px;
}

.quiz-option-btn.correct {
  background: #e8f5e9;
  border-color: #43a047;
  color: #1b5e20;
}

.quiz-option-btn.wrong {
  background: #fce4ec;
  border-color: #e53935;
  color: #880e4f;
}

[data-theme="dark"] .quiz-option-btn.correct {
  background: rgba(67,160,71,0.18); border-color: #66bb6a; color: #a5d6a7;
}
[data-theme="dark"] .quiz-option-btn.wrong {
  background: rgba(229,57,53,0.18); border-color: #ef5350; color: #ef9a9a;
}

.quiz-option-btn:disabled { cursor: default; }

.quiz-explanation {
  display: none;
  margin-top: 10px;
  padding: 10px 14px;
  background: var(--surface-alt);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.quiz-explanation.visible { display: block; }

.quiz-footer {
  text-align: center;
  padding: 16px 0 4px;
}

.quiz-test-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  background: var(--content-accent);
  color: #fff;
  border-radius: 24px;
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 600;
  transition: opacity var(--dur-fast);
}

.quiz-test-link:hover { opacity: 0.87; }

/* ── Breadcrumb ── */
.jee-breadcrumb {
  font-size: 0.75rem;
  color: var(--text-secondary);
  padding: 8px 20px 0;
  flex-shrink: 0;
}

.jee-breadcrumb a {
  color: var(--content-accent);
  text-decoration: none;
}

.jee-breadcrumb a:hover { text-decoration: underline; }

.jee-breadcrumb span + span::before { content: ' › '; color: var(--border); }

/* ── Topic header (shown inside content area) ── */
.topic-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--divider-light);
}

.topic-header__icon {
  font-size: 1.6rem;
  flex-shrink: 0;
}

.topic-header__title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--content-primary);
  margin: 0;
}

.topic-header__meta {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

.topic-header__mastery {
  margin-left: auto;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
  flex-shrink: 0;
}

.topic-header__mastery.not-started { background: var(--bg-secondary); color: var(--text-secondary); }
.topic-header__mastery.in-progress { background: #fff8e1; color: #6d4c00; }
.topic-header__mastery.mastered    { background: #e8f5e9; color: #2e7d32; }

[data-theme="dark"] .topic-header__mastery.in-progress { background: rgba(109,76,0,0.2); color: #ffe082; }
[data-theme="dark"] .topic-header__mastery.mastered    { background: rgba(46,125,50,0.2); color: #81c784; }

/* ── Inline formula (within theory text) ── */
.inline-formula {
  display: inline-block;
  font-family: 'Courier New', monospace;
  font-size: 0.92em;
  background: var(--surface-alt);
  padding: 1px 6px;
  border-radius: 3px;
  color: var(--content-primary);
}

[data-theme="dark"] .inline-formula { color: #63b3ed; }

/* ── Important note block ── */
.important-block {
  padding: 12px 16px;
  background: var(--surface-alt);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--content-accent);
  font-size: 0.84rem;
  line-height: 1.6;
  color: var(--text);
  margin: 14px 0;
}

/* ── Weak topic warning (driven by test scores) ── */
.topic-tab-pill.weak-topic::before {
  content: '⚠';
  font-size: 0.65rem;
  color: #f57c00;
  margin-right: 2px;
}

/* ═══════════════════════════════════════════
   MODULE OVERVIEW / WRAP-UP COMPONENTS
   (shared by any subject's "Overview" and
   "Revision & Practice" bookend topic panels)
═══════════════════════════════════════════ */

/* ── Learning objectives checklist ── */
.obj-list { list-style: none; padding-left: 0; margin: 0 0 10px; }
.obj-list li {
  position: relative;
  padding-left: 26px;
  margin-bottom: 8px;
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--text);
}
.obj-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  top: 0;
  color: var(--clr-success, #2e7d32);
  font-weight: 700;
}

/* ── Exam relevance stars ── */
.exam-relevance { display: flex; flex-wrap: wrap; gap: 10px 22px; margin: 10px 0 18px; }
.exam-relevance__item { display: flex; align-items: center; gap: 8px; font-size: 0.85rem; color: var(--text); }
.exam-relevance__label { font-weight: 600; min-width: 70px; }
.star-rating { color: #f9a825; letter-spacing: 1px; font-size: 0.9rem; }
.star-rating .dim { color: var(--divider-light); }

/* ── Concept map (vertical flow) ── */
.concept-map { display: flex; flex-direction: column; align-items: flex-start; margin: 10px 0 20px; }
.concept-map__node {
  background: var(--surface-alt);
  border: 1px solid var(--divider-light);
  border-radius: var(--radius-sm);
  padding: 8px 14px;
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--content-primary);
}
.concept-map__node.sub { margin-left: 28px; font-weight: 500; color: var(--text); }
.concept-map__arrow { padding: 2px 0 2px 14px; color: var(--content-accent); font-size: 0.9rem; }

/* ── Related topics / continue learning ── */
.related-topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 12px;
  margin: 10px 0 20px;
}
.related-topic-card {
  display: block;
  background: var(--card-bg);
  border: 1px solid var(--divider-light);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  text-decoration: none;
  transition: box-shadow var(--dur-fast);
}
.related-topic-card:hover { box-shadow: var(--shadow-md); }
.related-topic-card__label { font-size: 0.68rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; color: var(--content-accent); }
.related-topic-card__title { font-size: 0.88rem; font-weight: 600; color: var(--content-primary); margin-top: 3px; }

/* ── Practice question (self-attempt, answer hidden in <details>) ── */
.practice-question {
  background: var(--card-bg);
  border: 1px solid var(--divider-light);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  margin-bottom: 12px;
}
.practice-question__q { font-size: 0.88rem; color: var(--text); line-height: 1.6; margin-bottom: 8px; }
.practice-question__q .difficulty-badge { margin-right: 8px; vertical-align: middle; }
.practice-question details.practice-question__answer summary {
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--content-accent);
  list-style: none;
}
.practice-question details.practice-question__answer summary::-webkit-details-marker { display: none; }
.practice-question details.practice-question__answer summary::before { content: '▸ Show answer'; }
.practice-question details.practice-question__answer[open] summary::before { content: '▾ Hide answer'; }
.practice-question details.practice-question__answer .answer-body {
  margin-top: 8px;
  font-size: 0.84rem;
  line-height: 1.6;
  color: var(--text-secondary);
  padding-top: 8px;
  border-top: 1px dashed var(--divider-light);
}