/* ================================================================
   Linda's English Hub — 内容页面共用样式
   适用：gaokao.html / ielts.html
   ================================================================ */

/* ===== Section Header ===== */
.section-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-xl);
  flex-wrap: wrap;
}

.section-header h2 {
  font-size: var(--text-2xl);
  color: var(--color-text-main);
  margin: 0;
  white-space: nowrap;
}

/* ===== Sub-navigation Tabs ===== */
.sub-nav-tabs {
  display: flex;
  gap: 0;
  margin-bottom: var(--spacing-xl);
  border-bottom: 2px solid var(--color-border);
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
}

.sub-nav-tab {
  padding: 12px 24px;
  color: var(--color-text-muted);
  font-weight: var(--weight-medium);
  font-size: var(--text-md);
  cursor: pointer;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  transition: color var(--transition-fast), border-color var(--transition-fast);
  white-space: nowrap;
  background: none;
  border-top: none;
  border-left: none;
  border-right: none;
  font-family: inherit;
}

.sub-nav-tab:hover {
  color: var(--color-primary);
}

.sub-nav-tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: var(--weight-semibold);
}

/* ===== Vocabulary Browser ===== */
.vocab-toolbar {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
  align-items: center;
}

.search-box {
  flex: 1;
  min-width: 220px;
  position: relative;
}

.search-box input {
  width: 100%;
  padding: 10px 16px 10px 40px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-md);
  background: var(--color-surface);
  color: var(--color-text-main);
  transition: border-color var(--transition-fast);
}

.search-box input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-xlight);
}

.search-box .search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  font-size: var(--text-md);
}

.unit-selector {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.unit-chip {
  padding: 6px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: 20px;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--color-surface);
  white-space: nowrap;
}

.unit-chip:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.unit-chip.active {
  background: var(--color-primary);
  color: var(--color-surface);
  border-color: var(--color-primary);
}

.vocab-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.vocab-item {
  display: grid;
  grid-template-columns: 160px 80px 1fr auto;
  align-items: center;
  gap: var(--spacing-md);
  padding: 14px 18px;
  background: var(--color-surface);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background var(--transition-fast), box-shadow var(--transition-fast);
  border: 1px solid transparent;
}

.vocab-item:hover {
  background: var(--color-primary-xlight);
  border-color: var(--color-border);
}

.vocab-item.expanded {
  background: var(--color-primary-xlight);
  border-color: var(--color-primary);
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.vocab-word {
  font-weight: var(--weight-semibold);
  font-size: var(--text-lg);
  color: var(--color-text-main);
  display: flex;
  align-items: center;
  gap: 6px;
}

.vocab-word .speak-trigger {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: color var(--transition-fast);
  opacity: 0;
}

.vocab-word:hover .speak-trigger {
  opacity: 1;
}

.vocab-word .speak-trigger:hover {
  color: var(--color-primary);
}

.vocab-phonetic {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-style: italic;
}

.vocab-definition {
  color: var(--color-text-main);
  font-size: var(--text-md);
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.vocab-actions {
  display: flex;
  gap: 6px;
}

.btn-icon-sm {
  padding: 5px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-icon-sm:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-icon-sm.mastered {
  border-color: var(--color-success);
  color: var(--color-success);
  background: rgba(45,154,106,0.08);
}

.vocab-detail {
  display: none;
  padding: 0 18px 16px;
  background: var(--color-primary-xlight);
  border: 1px solid var(--color-primary);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  margin-top: -4px;
}

.vocab-detail.open {
  display: block;
}

.vocab-detail p {
  margin: 6px 0;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

.vocab-detail .example-en {
  color: var(--color-text-main);
  font-style: italic;
}

.vocab-detail .example-cn {
  color: var(--color-text-muted);
  margin-left: var(--spacing-sm);
}

.vocab-result-count {
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  margin-top: var(--spacing-lg);
}

.empty-state {
  text-align: center;
  padding: var(--spacing-3xl) var(--spacing-lg);
  color: var(--color-text-muted);
}

.empty-state .empty-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-md);
  opacity: 0.4;
}

.empty-state p {
  font-size: var(--text-lg);
  margin: 0;
}

/* ===== Grammar Accordion ===== */
.grammar-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.grammar-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-surface);
  transition: box-shadow var(--transition-fast);
}

.grammar-item:hover {
  box-shadow: 0 2px 8px rgba(212,83,126,0.08);
}

.grammar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.grammar-header:hover {
  background: var(--color-primary-xlight);
}

.grammar-header .grammar-title {
  font-weight: var(--weight-semibold);
  font-size: var(--text-md);
  color: var(--color-text-main);
  display: flex;
  align-items: center;
  gap: 10px;
}

.grammar-category {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 12px;
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
}

.grammar-toggle {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  transition: transform var(--transition-normal);
}

.grammar-item.open .grammar-toggle {
  transform: rotate(180deg);
}

.grammar-body {
  display: none;
  padding: 0 20px 20px;
  border-top: 1px solid var(--color-border);
}

.grammar-item.open .grammar-body {
  display: block;
}

.grammar-body .rule-content {
  font-size: var(--text-md);
  line-height: 1.8;
  color: var(--color-text-main);
}

.grammar-body .rule-content h4 {
  font-size: var(--text-lg);
  margin: 16px 0 8px;
  color: var(--color-primary-dark);
}

.grammar-body .rule-content ul {
  margin: 8px 0;
  padding-left: 20px;
}

.grammar-body .rule-content li {
  margin: 4px 0;
  color: var(--color-text-muted);
}

.grammar-body .examples-section {
  margin-top: var(--spacing-md);
  padding: var(--spacing-md);
  background: var(--color-primary-xlight);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-primary);
}

.grammar-body .examples-section p {
  margin: 4px 0;
  font-size: var(--text-sm);
  line-height: 1.6;
}

.grammar-body .examples-section .example-en {
  color: var(--color-text-main);
  font-style: italic;
}

.grammar-body .examples-section .example-cn {
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  margin-left: var(--spacing-sm);
}

.grammar-tips {
  margin-top: var(--spacing-md);
  padding: 12px 16px;
  background: linear-gradient(135deg, rgba(224,138,42,0.08), rgba(224,138,42,0.04));
  border-radius: var(--radius-sm);
  border: 1px solid rgba(224,138,42,0.2);
}

.grammar-tips .tips-label {
  font-weight: var(--weight-semibold);
  font-size: var(--text-sm);
  color: var(--color-warning);
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* ===== Writing Template Cards ===== */
.template-filters {
  display: flex;
  gap: 6px;
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
}

.template-filters .filter-chip {
  padding: 6px 14px;
  border: 1.5px solid var(--color-border);
  border-radius: 20px;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--color-surface);
  white-space: nowrap;
}

.template-filters .filter-chip:hover,
.template-filters .filter-chip.active {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-xlight);
}

.template-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: var(--spacing-lg);
}

.template-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  overflow: hidden;
  transition: box-shadow var(--transition-fast), transform var(--transition-fast);
}

.template-card:hover {
  box-shadow: 0 4px 16px rgba(212,83,126,0.1);
  transform: translateY(-2px);
}

.template-card-header {
  padding: 20px 20px 16px;
  border-bottom: 1px solid var(--color-border);
  background: linear-gradient(135deg, var(--color-primary-xlight), var(--color-surface));
}

.template-card-header .type-badge {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 12px;
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  background: var(--color-primary);
  color: white;
  margin-bottom: 8px;
}

.template-card-header .type-badge.task1 {
  background: #2196F3;
}

.template-card-header h3 {
  font-size: var(--text-lg);
  margin: 6px 0 4px;
  color: var(--color-text-main);
}

.template-card-header .overview {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.5;
}

.template-card-body {
  padding: 16px 20px;
}

.template-card-body h5 {
  font-size: var(--text-sm);
  color: var(--color-primary-dark);
  margin: 0 0 8px;
}

.template-card-body .structure-list {
  list-style: none;
  padding: 0;
  margin: 0 0 12px;
}

.template-card-body .structure-list li {
  padding: 4px 0;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.template-card-body .structure-list li::before {
  content: '▸';
  color: var(--color-primary);
  font-size: var(--text-xs);
  margin-top: 2px;
}

.linkers {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 12px;
}

.linker-tag {
  padding: 2px 10px;
  border-radius: 12px;
  font-size: var(--text-xs);
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  font-weight: var(--weight-medium);
}

.template-card-body .sample-text {
  padding: 10px 14px;
  background: var(--color-primary-xlight);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  line-height: 1.6;
  font-style: italic;
  border-left: 3px solid var(--color-primary);
}

.template-card-actions {
  padding: 12px 20px;
  border-top: 1px solid var(--color-border);
  display: flex;
  gap: 8px;
}

.btn-copy {
  padding: 6px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-copy:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-copy.copied {
  border-color: var(--color-success);
  color: var(--color-success);
  background: rgba(45,154,106,0.08);
}

/* ===== Speaking Topics ===== */
.speaking-tabs {
  display: flex;
  gap: 0;
  margin-bottom: var(--spacing-xl);
  border-bottom: 2px solid var(--color-border);
  overflow-x: auto;
  overflow-y: hidden;

.speaking-tab {
  padding: 10px 20px;
  border: none;
  background: none;
  font-size: var(--text-md);
  color: var(--color-text-muted);
  cursor: pointer;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  font-family: inherit;
  font-weight: var(--weight-medium);
  transition: all var(--transition-fast);
}

.speaking-tab:hover,
.speaking-tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.speaking-tab .badge-count {
  display: inline-block;
  padding: 1px 8px;
  border-radius: 10px;
  font-size: var(--text-xs);
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  margin-left: 6px;
}

.topic-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  overflow: hidden;
  margin-bottom: var(--spacing-lg);
  transition: box-shadow var(--transition-fast);
}

.topic-card:hover {
  box-shadow: 0 2px 12px rgba(212,83,126,0.08);
}

.topic-card-header {
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  border-bottom: 1px solid transparent;
  transition: background var(--transition-fast), border-color var(--transition-fast);
}

.topic-card.open .topic-card-header {
  border-bottom-color: var(--color-border);
  background: var(--color-primary-xlight);
}

.topic-card-header:hover {
  background: var(--color-primary-xlight);
}

.topic-card-header .topic-title {
  font-weight: var(--weight-semibold);
  font-size: var(--text-md);
  color: var(--color-text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.topic-card-body {
  display: none;
  padding: 16px 20px;
}

.topic-card.open .topic-card-body {
  display: block;
}

.topic-card-body .question-list {
  list-style: none;
  padding: 0;
  margin: 0 0 12px;
}

.topic-card-body .question-list li {
  padding: 6px 0;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.topic-card-body .question-list li::before {
  content: '💬';
  font-size: var(--text-sm);
  flex-shrink: 0;
}

.topic-card-body .vocab-section {
  margin-bottom: 12px;
}

.vocab-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.vocab-tags .vocab-tag {
  padding: 2px 10px;
  border-radius: 12px;
  font-size: var(--text-xs);
  background: rgba(33,150,243,0.08);
  color: #1976D2;
  font-weight: var(--weight-medium);
}

.topic-card-body .sample-answer {
  padding: 14px 16px;
  background: var(--color-primary-xlight);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--color-primary);
}

.topic-card-body .sample-answer .answer-label {
  font-weight: var(--weight-semibold);
  font-size: var(--text-xs);
  color: var(--color-primary);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.topic-card-body .sample-answer p {
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-text-main);
  margin: 0;
}

/* ===== Cue Card (Part 2) Special ===== */
.cue-card-list {
  list-style: disc;
  padding-left: 20px;
  margin: 6px 0;
}

.cue-card-list li {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin: 3px 0;
}

/* ===== Discussion Points (Part 3) ===== */
.discussion-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 10px;
}

.discussion-pill {
  padding: 3px 12px;
  border-radius: 12px;
  font-size: var(--text-xs);
  background: rgba(156,39,176,0.08);
  color: #7B1FA2;
  font-weight: var(--weight-medium);
}

/* ===== Random Practice Button ===== */
.random-practice {
  text-align: center;
  margin: var(--spacing-lg) 0;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .vocab-item {
    grid-template-columns: 120px 1fr;
    gap: 4px;
  }
  .vocab-item .vocab-phonetic {
    display: none;
  }
  .vocab-item .vocab-actions {
    grid-column: 1 / -1;
    justify-content: flex-end;
  }
  .template-grid {
    grid-template-columns: 1fr;
  }
  .section-header {
    flex-direction: column;
    align-items: flex-start;
  }
  .sub-nav-tab,
  .speaking-tab {
    padding: 10px 14px;
    font-size: var(--text-sm);
  }
}