:root {
  --ai-primary: #2D5A27;
  --ai-primary-hover: #1E3F19;
  --ai-primary-soft: #E1ECE2;
  --ai-primary-border: #c8dfcb;
  --ai-accent: #4F8549;
  --ai-accent-hover: #2e5b29;
  --ai-accent-soft: #ebf5ec;
  --ai-accent-border: #c6e3c8;
  --ai-warning: #d97706;
  --ai-warning-soft: #fffbeb;
  --ai-warning-border: #fde68a;
  --ai-error: #dc2626;
  --ai-error-soft: #fef2f2;
  --ai-error-border: #fecaca;
  --ai-bg: #F7F9F6;
  --ai-surface: #ffffff;
  --ai-surface-muted: #edf5ee;
  --ai-ink: #233322;
  --ai-ink-secondary: #3b4e39;
  --ai-muted: #5F745E;
  --ai-line: #E2EBE2;
  --ai-line-strong: #c8d8c7;
  --ai-shadow: 0 4px 20px -2px rgba(20, 41, 30, 0.06), 0 2px 6px -1px rgba(20, 41, 30, 0.03);
  --ai-radius-sm: 8px;
  --ai-radius: 12px;
  --ai-radius-lg: 16px;
  --ai-radius-full: 9999px;
  --ai-font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

/* Floating Launcher Button */
.ai-qa-launcher {
  position: fixed;
  right: max(20px, env(safe-area-inset-right));
  bottom: max(20px, env(safe-area-inset-bottom));
  z-index: 10000045;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  box-sizing: border-box;
  min-width: 112px;
  height: 44px;
  padding: 0 16px;
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: var(--ai-radius-full);
  background: rgba(255, 255, 255, 0.45);
  color: var(--ai-primary);
  box-shadow: 0 4px 18px rgba(37, 99, 235, 0.12);
  backdrop-filter: blur(14px) saturate(1.25);
  -webkit-backdrop-filter: blur(14px) saturate(1.25);
  opacity: 0.65;
  font-family: inherit;
  font-size: 0.92rem;
  font-weight: 750;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  cursor: grab;
  user-select: none;
  touch-action: none;
  appearance: none;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, opacity 0.18s ease;
}

.ai-qa-launcher svg {
  width: 18px;
  height: 18px;
  stroke-width: 2.2;
}

.ai-qa-launcher:hover {
  transform: translateY(-2px);
  background: #ffffff;
  opacity: 1;
  box-shadow: 0 14px 34px rgba(37, 99, 235, 0.25), inset 0 1px 0 #ffffff;
}

.ai-qa-launcher.is-dragging,
.ai-qa-launcher.is-dragging:hover {
  cursor: grabbing;
  transform: none;
  transition: none;
}

.ai-qa-launcher:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.35);
  outline-offset: 3px;
}

body.ai-qa-open {
  overflow: hidden;
}

/* Modal Overlay & Drawer Panel */
.ai-qa-overlay {
  position: fixed;
  inset: 0;
  z-index: 10000090;
  display: flex;
  justify-content: flex-end;
  background: rgba(15, 23, 42, 0.38);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  animation: ai-fade-in 0.2s ease-out;
}

@keyframes ai-fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

.ai-qa-overlay[hidden],
.ai-qa-status[hidden] {
  display: none;
}

.ai-qa-panel {
  width: clamp(520px, 60vw, 940px);
  height: 100%;
  display: flex;
  flex-direction: column;
  background: var(--ai-bg);
  color: var(--ai-ink);
  box-shadow: -20px 0 60px rgba(0, 0, 0, 0.18);
  border-left: 1px solid var(--ai-line);
  animation: ai-slide-in 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes ai-slide-in {
  from { transform: translateX(100%); }
  to { transform: translateX(0); }
}

.ai-qa-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 24px 12px;
  background: var(--ai-surface);
  border-bottom: 1px solid var(--ai-line);
}

.ai-qa-header-title {
  display: flex;
  align-items: center;
  gap: 10px;
}

.ai-qa-header h2 {
  margin: 0;
  font-size: 1.25rem;
  line-height: 1.2;
  font-weight: 800;
  color: var(--ai-ink);
  letter-spacing: -0.02em;
}

.ai-qa-header-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border-radius: var(--ai-radius-full);
  background: var(--ai-accent-soft);
  border: 1px solid var(--ai-accent-border);
  color: var(--ai-accent-hover);
  font-size: 0.76rem;
  font-weight: 750;
}

.ai-qa-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ai-accent);
  box-shadow: 0 0 0 2.5px rgba(16, 185, 129, 0.25);
  animation: ai-pulse 2s infinite;
}

@keyframes ai-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.7; transform: scale(1.15); }
}

.ai-qa-icon-btn {
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--ai-line);
  border-radius: 50%;
  background: var(--ai-surface);
  color: var(--ai-muted);
  cursor: pointer;
  transition: all 0.16s ease;
}

.ai-qa-icon-btn:hover {
  background: var(--ai-surface-muted);
  color: var(--ai-ink);
  border-color: var(--ai-line-strong);
}

.ai-qa-icon-btn svg {
  width: 18px;
  height: 18px;
}

.ai-qa-status {
  margin: 12px 24px 0;
  padding: 10px 14px;
  border: 1px solid var(--ai-warning-border);
  border-radius: var(--ai-radius);
  background: var(--ai-warning-soft);
  color: var(--ai-warning);
  font-size: 0.84rem;
  line-height: 1.5;
  font-weight: 600;
}

/* Tabs Bar (Ask / Quiz / History) */
.ai-qa-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 4px;
  margin: 14px 24px 0;
  padding: 4px;
  border-radius: var(--ai-radius);
  background: var(--ai-surface-muted);
  border: 1px solid var(--ai-line);
}

.ai-qa-tabs button {
  height: 36px;
  border: 0;
  border-radius: 9px;
  background: transparent;
  color: var(--ai-muted);
  font: inherit;
  font-size: 0.88rem;
  font-weight: 750;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: all 0.16s ease;
}

.ai-qa-tabs button:hover {
  color: var(--ai-ink);
}

.ai-qa-tabs button[aria-selected="true"] {
  background: #ffffff;
  color: var(--ai-primary);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.ai-qa-body {
  flex: 1;
  min-height: 0;
  overflow: auto;
  padding: 18px 24px 32px;
}

/* Form Controls */
.ai-qa-form {
  display: grid;
  gap: 14px;
}

.ai-qa-form label {
  display: grid;
  gap: 6px;
  color: var(--ai-ink-secondary);
  font-size: 0.84rem;
  font-weight: 750;
}

.ai-qa-control-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.7fr;
  gap: 12px;
}

.ai-qa-control-grid:has(label:nth-child(3)) {
  grid-template-columns: 1fr 1fr 0.7fr;
}

.ai-qa-form select,
.ai-qa-form input,
.ai-qa-form textarea {
  width: 100%;
  box-sizing: border-box;
  border: 1px solid var(--ai-line-strong);
  border-radius: var(--ai-radius-sm);
  background: #ffffff;
  color: var(--ai-ink);
  font: inherit;
  font-size: 0.9rem;
  font-weight: 500;
  line-height: 1.45;
  outline: none;
  transition: border-color 0.16s ease, box-shadow 0.16s ease;
}

.ai-qa-form select,
.ai-qa-form input {
  height: 42px;
  padding: 0 12px;
}

.ai-qa-form textarea {
  min-height: 120px;
  resize: vertical;
  padding: 12px 14px;
  line-height: 1.6;
}

.ai-qa-form select:focus,
.ai-qa-form input:focus,
.ai-qa-form textarea:focus {
  border-color: var(--ai-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.ai-qa-primary-btn {
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid rgba(45, 90, 39, 0.25);
  border-radius: 12px;
  background: #E1ECE2;
  color: #245220;
  font: inherit;
  font-size: 0.94rem;
  font-weight: 800;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(45, 90, 39, 0.06);
  transition: all 0.18s cubic-bezier(0.16, 1, 0.3, 1);
}

.ai-qa-primary-btn:hover {
  background: #d4e8d6;
  border-color: rgba(45, 90, 39, 0.4);
  color: #173b14;
  box-shadow: 0 4px 14px rgba(45, 90, 39, 0.12);
  transform: translateY(-1px);
}

.ai-qa-primary-btn:active {
  background: #c6e0c9;
  transform: translateY(0) scale(0.99);
}

.ai-qa-primary-btn:disabled {
  cursor: wait;
  opacity: 0.6;
  background: #edf3ee;
  color: #7b947a;
  border-color: #d8e2d9;
  transform: none;
}

.ai-qa-primary-btn svg {
  width: 17px;
  height: 17px;
}

/* Results Container */
.ai-qa-result {
  margin-top: 18px;
  display: grid;
  gap: 14px;
}

/* Loading Card & Tabular Stable Timer (No Jitter!) */
.ai-qa-loading-card {
  border: 1px solid var(--ai-primary-border);
  border-radius: var(--ai-radius);
  padding: 18px 20px;
  background: linear-gradient(135deg, #eff6ff 0%, #ffffff 100%);
  display: grid;
  gap: 12px;
  box-shadow: var(--ai-shadow);
}

.ai-qa-loading-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: nowrap;
  width: 100%;
}

.ai-qa-loading-title-group {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 0;
  overflow: hidden;
}

.ai-qa-spinner {
  width: 20px;
  height: 20px;
  border: 2.5px solid var(--ai-primary-border);
  border-top-color: var(--ai-primary);
  border-radius: 50%;
  animation: ai-spin 0.8s linear infinite;
  flex-shrink: 0;
}

@keyframes ai-spin {
  to { transform: rotate(360deg); }
}

.ai-qa-loading-title {
  font-size: 0.92rem;
  font-weight: 750;
  color: var(--ai-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.ai-qa-timer-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 3px 8px;
  background: #ffffff;
  border: 1px solid var(--ai-primary-border);
  border-radius: var(--ai-radius-full);
  color: var(--ai-primary);
  font-family: var(--ai-font-mono);
  font-size: 0.76rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  flex-shrink: 0;
  box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.ai-qa-loading-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 5px;
  width: 100%;
  box-sizing: border-box;
}

.ai-qa-step-chip {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 4px 2px;
  border-radius: var(--ai-radius-full);
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--ai-line);
  font-size: 0.70rem;
  color: var(--ai-muted);
  white-space: nowrap;
  box-sizing: border-box;
  transition: all 0.2s ease;
  user-select: none;
}

.ai-qa-step-chip.active {
  background: var(--ai-primary);
  border-color: var(--ai-primary);
  color: #ffffff;
  font-weight: 800;
  box-shadow: 0 2px 6px rgba(13, 148, 136, 0.18);
}

.ai-qa-step-chip.done {
  background: var(--ai-primary-soft);
  border-color: var(--ai-primary-border);
  color: var(--ai-primary);
  font-weight: 750;
}

/* Q&A Answer Card */
.ai-qa-answer-card {
  border: 1px solid var(--ai-line);
  border-radius: var(--ai-radius);
  background: var(--ai-surface);
  padding: 20px;
  box-shadow: var(--ai-shadow);
  display: grid;
  gap: 14px;
}

.ai-qa-answer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--ai-line);
  padding-bottom: 10px;
}

.ai-qa-answer-title {
  font-size: 0.94rem;
  font-weight: 800;
  color: var(--ai-ink);
  display: flex;
  align-items: center;
  gap: 6px;
}

.ai-qa-copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border: 1px solid var(--ai-line-strong);
  border-radius: 6px;
  background: #ffffff;
  color: var(--ai-muted);
  cursor: pointer;
  font-size: 0.78rem;
  font-weight: 650;
  transition: all 0.15s ease;
}

.ai-qa-copy-btn:hover {
  color: var(--ai-primary);
  border-color: var(--ai-primary-border);
  background: var(--ai-primary-soft);
}

.ai-qa-text {
  color: var(--ai-ink);
  font-size: 0.92rem;
  line-height: 1.75;
  white-space: pre-wrap;
}

.ai-qa-answer-callout {
  border: 1px solid var(--ai-accent-border);
  border-radius: var(--ai-radius-sm);
  padding: 10px 14px;
  margin-bottom: 10px;
  background: var(--ai-accent-soft);
}

.ai-qa-answer-callout.is-summary {
  background: linear-gradient(135deg, var(--ai-accent-soft) 0%, #ffffff 100%);
}

.ai-qa-answer-callout.is-mnemonic {
  background: linear-gradient(135deg, var(--ai-warning-soft) 0%, #ffffff 100%);
  border-color: var(--ai-warning-border);
}

.ai-qa-answer-label {
  margin-bottom: 4px;
  color: var(--ai-accent-hover);
  font-size: 0.8rem;
  font-weight: 850;
}

.ai-qa-answer-callout.is-mnemonic .ai-qa-answer-label {
  color: var(--ai-warning);
}

.ai-qa-answer-points {
  margin: 8px 0 12px;
  padding: 0;
  display: grid;
  gap: 8px;
  list-style: none;
  white-space: normal;
  border: 0;
  background: transparent;
}

.ai-qa-answer-points li {
  padding: 2px 0;
  color: var(--ai-ink);
  line-height: 1.68;
  list-style: none;
}

.ai-qa-point-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.35rem;
  height: 1.35rem;
  padding: 0 5px;
  margin-right: 6px;
  background: var(--ai-accent-soft, #e0f2fe);
  color: var(--ai-accent-hover, #0284c7);
  border-radius: 4px;
  font-size: 0.76rem;
  font-weight: 800;
  vertical-align: middle;
}

.ai-qa-point-title {
  color: var(--ai-ink);
  font-weight: 800;
}

.ai-qa-sub-points {
  margin: 4px 0 6px 1.45rem;
  padding: 0;
  list-style-type: disc;
  display: grid;
  gap: 3px;
  color: var(--ai-ink);
  font-size: 0.88rem;
}

.ai-qa-sub-points li {
  padding: 1px 0 !important;
  line-height: 1.55 !important;
  border-bottom: 0 !important;
  list-style: disc !important;
}

.ai-qa-sub-points li::marker {
  color: var(--ai-primary, #0d9488);
  font-size: 0.8em;
}

.ai-qa-live-card {
  border-style: dashed !important;
  border-color: rgba(13, 148, 136, 0.25) !important;
  background: rgba(255, 255, 255, 0.95) !important;
}

.ai-qa-stream-hint {
  font-size: 0.86rem;
  color: var(--ai-primary, #0d9488);
  font-weight: 750;
  padding: 6px 0;
}

/* Question Cards & Interactive Options */
.ai-qa-question-card {
  border: 1px solid var(--ai-line);
  border-radius: var(--ai-radius);
  background: var(--ai-surface);
  padding: 14px 14px;
  margin-top: 10px;
  box-shadow: var(--ai-shadow);
  display: grid;
  gap: 10px;
}

.ai-qa-question-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.ai-qa-badge-group {
  display: flex;
  align-items: center;
  gap: 6px;
}

.ai-qa-number-badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: var(--ai-radius-full);
  background: var(--ai-primary-soft);
  border: 1px solid var(--ai-primary-border);
  color: var(--ai-primary);
  font-size: 0.8rem;
  font-weight: 800;
  font-family: var(--ai-font-mono);
}

.ai-qa-tag-badge {
  padding: 2px 7px;
  border-radius: 6px;
  background: var(--ai-surface-muted);
  color: var(--ai-ink-secondary);
  font-size: 0.76rem;
  font-weight: 700;
}

.ai-qa-question-card h4 {
  margin: 0;
  color: var(--ai-ink);
  font-size: 0.98rem;
  line-height: 1.6;
  font-weight: 650;
}

.ai-qa-options {
  display: grid;
  gap: 8px;
  margin-top: 4px;
}

.ai-qa-option-card {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px 14px;
  border: 1px solid var(--ai-line);
  border-radius: var(--ai-radius-sm);
  background: var(--ai-surface);
  cursor: pointer;
  text-align: left;
  transition: all 0.15s ease;
  user-select: none;
}

.ai-qa-option-card:hover {
  border-color: var(--ai-primary-border);
  background: var(--ai-primary-soft);
  transform: translateX(2px);
}

.ai-qa-option-letter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--ai-surface-muted);
  border: 1px solid var(--ai-line-strong);
  color: var(--ai-ink-secondary);
  font-size: 0.82rem;
  font-weight: 800;
  font-family: var(--ai-font-mono);
  flex-shrink: 0;
  transition: all 0.15s ease;
}

.ai-qa-option-text {
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--ai-ink);
  padding-top: 1px;
}

.ai-qa-option-card.selected {
  border-color: var(--ai-primary);
  background: var(--ai-primary-soft);
}
.ai-qa-option-card.selected .ai-qa-option-letter {
  background: var(--ai-primary);
  border-color: var(--ai-primary);
  color: #ffffff;
}

.ai-qa-option-card.is-correct {
  border-color: var(--ai-accent);
  background: var(--ai-accent-soft);
}
.ai-qa-option-card.is-correct .ai-qa-option-letter {
  background: var(--ai-accent);
  border-color: var(--ai-accent);
  color: #ffffff;
}

.ai-qa-option-card.is-wrong {
  border-color: var(--ai-error);
  background: var(--ai-error-soft);
}
.ai-qa-option-card.is-wrong .ai-qa-option-letter {
  background: var(--ai-error);
  border-color: var(--ai-error);
  color: #ffffff;
}

.ai-qa-answer-details {
  border: 0;
  background: transparent;
  margin-top: 4px;
}

.ai-qa-answer summary {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  color: var(--ai-primary, #0d9488);
  font-size: 0.82rem;
  font-weight: 750;
  padding: 3px 8px;
  border-radius: 6px;
  background: rgba(13, 148, 136, 0.08);
  border: 1px solid rgba(79, 70, 229, 0.18);
  user-select: none;
  transition: background 0.15s ease;
}

.ai-qa-answer summary:hover {
  background: rgba(13, 148, 136, 0.14);
}

.ai-qa-answer-body {
  padding: 8px 0;
  display: grid;
  gap: 8px;
}

.ai-qa-quiz-section {
  margin-top: 6px;
  padding: 9px 11px;
  border-radius: 8px;
  background: #ffffff;
  border: 1px solid var(--ai-line);
}

.ai-qa-ans-sec {
  border-left: 3px solid #16a34a;
  background: #f0fdf4;
}

.ai-qa-exp-sec {
  border-left: 3px solid #2563eb;
  background: #f8fafc;
}

.ai-qa-note-sec {
  border-left: 4px solid #d97706;
  background: #fffbeb;
}

.ai-qa-quiz-sec-title {
  font-size: 0.82rem;
  font-weight: 800;
  margin-bottom: 5px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.ai-qa-ans-sec .ai-qa-quiz-sec-title {
  color: #15803d;
}

.ai-qa-exp-sec .ai-qa-quiz-sec-title {
  color: #1d4ed8;
}

.ai-qa-note-sec .ai-qa-quiz-sec-title {
  color: #b45309;
}

.ai-qa-quiz-sec-body {
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--ai-ink);
}

.ai-qa-choice-ans {
  font-size: 0.9rem;
  font-weight: 700;
  color: #15803d;
  padding: 2px 0;
}

.ai-qa-sec-header {
  font-size: 0.9rem;
  font-weight: 850;
  color: #1e3a8a;
  margin: 8px 0 4px;
  padding-bottom: 2px;
  border-bottom: 1px dashed rgba(59, 130, 246, 0.2);
}

.ai-qa-quiz-sources-bar {
  margin-top: 8px;
  padding: 5px 8px;
  background: rgba(241, 245, 249, 0.85);
  border-radius: 6px;
  font-size: 0.78rem;
  color: var(--ai-muted);
  display: flex;
  align-items: center;
  gap: 5px;
  flex-wrap: wrap;
}

.ai-qa-source-chip {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 6px;
  background: #e2e8f0;
  color: var(--ai-ink);
  font-weight: 750;
  font-size: 0.76rem;
}

.ai-qa-answer-banner {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 6px;
  background: var(--ai-accent-soft);
  border: 1px solid var(--ai-accent-border);
  color: var(--ai-accent-hover);
  font-size: 0.88rem;
  font-weight: 750;
}

.ai-qa-answer-banner strong {
  font-size: 1rem;
}

.ai-qa-explanation-box {
  padding: 10px 12px;
  border-radius: 6px;
  background: #ffffff;
  border: 1px solid var(--ai-line);
  color: var(--ai-ink);
  font-size: 0.88rem;
  line-height: 1.6;
}

/* History Tab & Panel inside Drawer */
.ai-qa-history-container {
  display: grid;
  gap: 12px;
}

.ai-qa-history-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--ai-line);
  padding-bottom: 10px;
}

.ai-qa-history-filters {
  display: inline-flex;
  gap: 4px;
}

.ai-qa-filter-btn {
  border: 0;
  border-radius: 6px;
  padding: 4px 10px;
  background: transparent;
  color: var(--ai-muted);
  font-size: 0.8rem;
  font-weight: 750;
  cursor: pointer;
  transition: all 0.15s ease;
}

.ai-qa-filter-btn.active {
  background: var(--ai-primary-soft);
  color: var(--ai-primary);
}

.ai-qa-clear-btn {
  border: 1px solid var(--ai-line-strong);
  border-radius: 6px;
  padding: 4px 10px;
  background: #ffffff;
  color: var(--ai-muted);
  font-size: 0.78rem;
  font-weight: 650;
  cursor: pointer;
}

.ai-qa-clear-btn:hover {
  color: var(--ai-error);
  border-color: var(--ai-error-border);
  background: var(--ai-error-soft);
}

.ai-qa-history-list {
  display: grid;
  gap: 8px;
}

.ai-qa-history-item {
  display: grid;
  gap: 4px;
  padding: 12px 14px;
  border: 1px solid var(--ai-line);
  border-radius: var(--ai-radius-sm);
  background: #ffffff;
  color: var(--ai-ink);
  cursor: pointer;
  text-align: left;
  transition: all 0.15s ease;
}

.ai-qa-history-item:hover {
  border-color: var(--ai-primary-border);
  background: var(--ai-primary-soft);
  transform: translateY(-1px);
}

.ai-qa-history-item strong {
  font-size: 0.9rem;
  color: var(--ai-ink);
}

.ai-qa-history-item-sub {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--ai-muted);
}

.ai-qa-source-details {
  margin-top: 10px;
}

.ai-qa-source-details summary {
  cursor: pointer;
  color: var(--ai-accent-hover);
  font-size: 0.84rem;
  font-weight: 750;
  padding: 4px 0;
}

.ai-qa-source-list {
  display: grid;
  gap: 8px;
  margin-top: 8px;
}

.ai-qa-source-card {
  border: 1px solid var(--ai-line);
  border-radius: var(--ai-radius-sm);
  background: #ffffff;
  padding: 10px 12px;
}

.ai-qa-source-card strong {
  display: block;
  font-size: 0.86rem;
  color: var(--ai-ink);
}

.ai-qa-source-card span {
  display: block;
  margin-top: 2px;
  color: var(--ai-muted);
  font-size: 0.76rem;
}

.ai-qa-source-card p {
  margin: 6px 0 0;
  color: var(--ai-ink-secondary);
  font-size: 0.82rem;
  line-height: 1.5;
}

/* Dark Theme Compatibility */
body.dark-theme .ai-qa-launcher,
body[data-theme="dark"] .ai-qa-launcher {
  background: rgba(30, 41, 59, 0.9);
  color: #60a5fa;
  border-color: rgba(96, 165, 250, 0.3);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.4);
}

body.dark-theme .ai-qa-panel,
body[data-theme="dark"] .ai-qa-panel {
  background: #0f172a;
  color: #f1f5f9;
  border-left-color: rgba(255, 255, 255, 0.1);
}

body.dark-theme .ai-qa-header,
body.dark-theme .ai-qa-answer-card,
body.dark-theme .ai-qa-question-card,
body.dark-theme .ai-qa-option-card,
body.dark-theme .ai-qa-history-item,
body.dark-theme .ai-qa-source-card,
body[data-theme="dark"] .ai-qa-header,
body[data-theme="dark"] .ai-qa-answer-card,
body[data-theme="dark"] .ai-qa-question-card,
body[data-theme="dark"] .ai-qa-option-card,
body[data-theme="dark"] .ai-qa-history-item,
body[data-theme="dark"] .ai-qa-source-card {
  background: #1e293b;
  border-color: rgba(255, 255, 255, 0.08);
  color: #f1f5f9;
}

body.dark-theme .ai-qa-form select,
body.dark-theme .ai-qa-form input,
body.dark-theme .ai-qa-form textarea,
body[data-theme="dark"] .ai-qa-form select,
body[data-theme="dark"] .ai-qa-form input,
body[data-theme="dark"] .ai-qa-form textarea {
  background: #1e293b;
  border-color: rgba(255, 255, 255, 0.12);
  color: #f1f5f9;
}

/* Mobile Responsiveness */
@media (max-width: 640px) {
  .ai-qa-launcher {
    right: 14px;
    bottom: max(14px, env(safe-area-inset-bottom));
    min-width: 100px;
    height: 40px;
    padding: 0 13px;
  }

  .ai-qa-panel {
    width: 100vw;
  }

  .ai-qa-header,
  .ai-qa-body {
    padding-left: 10px;
    padding-right: 10px;
  }

  .ai-qa-question-card {
    padding: 10px 9px;
  }

  .ai-qa-quiz-section {
    padding: 8px 9px;
  }

  .ai-qa-tabs,
  .ai-qa-status {
    margin-left: 10px;
    margin-right: 10px;
  }

  .ai-qa-control-grid,
  .ai-qa-control-grid:has(label:nth-child(3)) {
    grid-template-columns: 1fr;
  }
}

.ai-qa-stream-cursor {
  display: inline-block;
  width: 2px;
  height: 1.15em;
  vertical-align: text-bottom;
  background-color: var(--ai-accent, #2563eb);
  margin-left: 4px;
  border-radius: 1px;
  animation: ai-qa-cursor-blink 0.8s infinite;
}

@keyframes ai-qa-cursor-blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

/* Custom Chapter Select Button in AI QA Launcher */
.ai-qa-custom-select {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  width: 100%;
  height: 38px;
  padding: 0 10px;
  border-radius: var(--ai-radius-sm, 8px);
  border: 1px solid var(--ai-line, #cbd5e1);
  background: var(--ai-surface, #ffffff);
  color: var(--ai-ink, #1e293b);
  font-size: 0.88rem;
  font-weight: 550;
  cursor: pointer;
  text-align: left;
  user-select: none;
  transition: all 0.15s ease;
  box-sizing: border-box;
}

.ai-qa-custom-select:hover {
  border-color: var(--ai-primary, #0d9488);
  background: rgba(13, 148, 136, 0.04);
}

.ai-qa-custom-select svg {
  color: #64748b;
  flex-shrink: 0;
}

.ai-qa-select-text {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
}

/* Chapter Picker Bottom Sheet / Modal for Launcher */
.ai-chapter-picker-overlay {
  position: fixed;
  inset: 0;
  z-index: 10000200;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.22s ease, visibility 0.22s ease;
}

.ai-chapter-picker-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.ai-chapter-picker-modal {
  width: 100%;
  max-width: 440px;
  max-height: 52vh;
  background: var(--ai-surface, #ffffff);
  border-radius: 16px 16px 0 0;
  box-shadow: 0 -6px 28px rgba(0, 0, 0, 0.16);
  display: flex;
  flex-direction: column;
  transform: translateY(100%);
  transition: transform 0.22s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
  box-sizing: border-box;
}

.ai-chapter-picker-modal.is-compact {
  max-height: 40vh;
}

.ai-chapter-picker-overlay.is-open .ai-chapter-picker-modal {
  transform: translateY(0);
}

@media (min-width: 641px) {
  .ai-chapter-picker-overlay {
    align-items: center;
  }
  .ai-chapter-picker-modal {
    border-radius: 14px;
    max-height: 48vh;
    transform: translateY(16px) scale(0.97);
    transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.2s ease;
  }
  .ai-chapter-picker-modal.is-compact {
    max-height: 36vh;
  }
  .ai-chapter-picker-overlay.is-open .ai-chapter-picker-modal {
    transform: translateY(0) scale(1);
  }
}

.ai-chapter-picker-handle {
  width: 32px;
  height: 4px;
  background: #cbd5e1;
  border-radius: 99px;
  margin: 6px auto 0;
}

@media (min-width: 641px) {
  .ai-chapter-picker-handle {
    display: none;
  }
}

.ai-chapter-picker-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px 4px;
}

.ai-chapter-picker-title {
  font-size: 0.96rem;
  font-weight: 800;
  color: var(--ai-ink, #0f172a);
}

.ai-chapter-picker-subtitle {
  font-size: 0.74rem;
  color: var(--ai-muted, #64748b);
  margin-top: 1px;
}

.ai-chapter-picker-close-btn {
  width: 28px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 0;
  background: #f1f5f9;
  color: #64748b;
  font-size: 0.88rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.ai-chapter-picker-close-btn:hover {
  background: #e2e8f0;
  color: #0f172a;
}

.ai-chapter-picker-search-wrap {
  position: relative;
  margin: 2px 14px 8px;
  display: flex;
  align-items: center;
}

.ai-chapter-picker-search-wrap svg {
  position: absolute;
  left: 10px;
  color: #94a3b8;
  pointer-events: none;
}

.ai-chapter-picker-search-input {
  width: 100%;
  height: 34px;
  padding: 0 10px 0 30px;
  border-radius: 8px;
  border: 1px solid #e2e8f0;
  background: #f8fafc;
  font-size: 0.84rem;
  color: var(--ai-ink, #0f172a);
  box-sizing: border-box;
  outline: none;
  transition: all 0.15s ease;
}

.ai-chapter-picker-search-input:focus {
  border-color: var(--ai-primary, #0d9488);
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.14);
}

.ai-chapter-picker-list {
  flex: 1;
  overflow-y: auto;
  padding: 0 12px 12px;
  display: grid;
  gap: 5px;
  box-sizing: border-box;
  -webkit-overflow-scrolling: touch;
}

.ai-chapter-picker-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 7px 10px;
  border-radius: 8px;
  border: 1px solid #f1f5f9;
  background: #ffffff;
  cursor: pointer;
  text-align: left;
  transition: all 0.15s ease;
  user-select: none;
}

.ai-chapter-picker-item:hover {
  border-color: rgba(13, 148, 136, 0.25);
  background: #f8fafc;
}

.ai-chapter-picker-item.is-selected {
  border-color: var(--ai-primary, #0d9488);
  background: rgba(13, 148, 136, 0.07);
}

.ai-chapter-picker-item-left {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 0;
}

.ai-chapter-picker-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px;
  height: 24px;
  padding: 0 6px;
  border-radius: 6px;
  background: #f1f5f9;
  color: #475569;
  font-size: 0.76rem;
  font-weight: 800;
  font-family: var(--font-mono, monospace);
  flex-shrink: 0;
}

.ai-chapter-picker-item.is-selected .ai-chapter-picker-badge {
  background: var(--ai-primary, #0d9488);
  color: #ffffff;
}

.ai-chapter-picker-badge.is-all {
  background: #ecfdf5;
  color: #059669;
  font-weight: 900;
}

.ai-chapter-picker-item-info {
  flex: 1;
  min-width: 0;
}

.ai-chapter-picker-item-title {
  font-size: 0.9rem;
  font-weight: 650;
  color: var(--ai-ink, #0f172a);
  line-height: 1.4;
  word-break: break-word;
}

.ai-chapter-picker-item.is-selected .ai-chapter-picker-item-title {
  color: var(--ai-primary, #0d9488);
  font-weight: 800;
}

.ai-chapter-picker-item-desc {
  font-size: 0.75rem;
  color: #64748b;
  margin-top: 2px;
}

.ai-chapter-picker-item-check {
  font-size: 0.95rem;
  font-weight: 900;
  color: var(--ai-primary, #0d9488);
  margin-left: 8px;
  flex-shrink: 0;
  width: 16px;
  text-align: center;
}