/* ========== Home / Dashboard ========== */
.home-hero {
  text-align: center;
  padding: 48px 24px;
  background: linear-gradient(135deg, #667EEA 0%, #764BA2 100%);
  border-radius: var(--radius-lg);
  color: #fff;
  margin-bottom: 32px;
}

.home-hero h1 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.home-hero p {
  opacity: 0.85;
  font-size: var(--fs-lg);
}

.home-quick-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}

.quick-stat {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
  display: flex;
  align-items: center;
  gap: 16px;
}

.quick-stat .qs-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
}

.quick-stat .qs-icon.words { background: var(--color-primary-bg); }
.quick-stat .qs-icon.grammar { background: var(--color-success-bg); }
.quick-stat .qs-icon.reading { background: var(--color-warning-bg); }
.quick-stat .qs-icon.streak { background: var(--color-danger-bg); }

.quick-stat .qs-value {
  font-size: var(--fs-2xl);
  font-weight: 800;
  color: var(--color-text);
}

.quick-stat .qs-label {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}

/* ========== Vocabulary Pages ========== */
.unit-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
  padding: 20px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.unit-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-md);
}

.unit-card h4 {
  font-size: var(--fs-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 4px;
}

.unit-card .unit-word-count {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}

.vocab-mode-selector {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
}

.mode-tab {
  padding: 8px 18px;
  border-radius: 20px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  background: var(--bg-hover);
  transition: all var(--transition-fast);
}

.mode-tab.active {
  background: var(--color-primary);
  color: #fff;
}

/* ========== Grammar Detail ========== */
.grammar-detail {
  max-width: 800px;
}

.grammar-formula {
  background: var(--color-primary-bg);
  border: 1px dashed var(--color-primary-light);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  text-align: center;
  font-size: var(--fs-lg);
  font-weight: 700;
  color: var(--color-primary-dark);
  font-family: Georgia, "Times New Roman", serif;
  margin: 20px 0;
}

.grammar-example {
  padding: 16px 20px;
  border-left: 3px solid var(--color-primary);
  background: var(--bg-hover);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 12px;
}

.grammar-example .en {
  font-family: Georgia, serif;
  color: var(--color-text);
  font-weight: 500;
}

.grammar-example .zh {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  margin-top: 4px;
}

.grammar-mistake {
  padding: 14px 18px;
  background: var(--color-danger-bg);
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
  font-size: var(--fs-sm);
}

.grammar-mistake .wrong {
  color: var(--color-danger);
  text-decoration: line-through;
}

.grammar-mistake .right {
  color: var(--color-success);
  font-weight: 600;
}

/* ========== Listening Page ========== */
.listening-controls {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.speed-btn {
  padding: 6px 14px;
  border-radius: 20px;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  background: var(--bg-hover);
  transition: all var(--transition-fast);
}

.speed-btn.active {
  background: var(--color-primary);
  color: #fff;
}

.listening-play-btn {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-size: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-fast);
  margin: 32px auto;
}

.listening-play-btn:hover {
  transform: scale(1.1);
  background: var(--color-primary-dark);
}

.listening-answer {
  font-size: var(--fs-2xl);
  font-weight: 700;
  text-align: center;
  padding: 20px;
  color: var(--color-success);
  animation: fadeIn 0.5s ease;
}

/* ========== Exam Page ========== */
.exam-section {
  margin-bottom: 32px;
}

.exam-section h3 {
  font-size: var(--fs-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-primary);
}

.exam-submit-area {
  text-align: center;
  padding: 32px;
}

/* ========== Error Book ========== */
.error-list {
  max-width: 800px;
}

.error-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px 18px;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border-light);
  margin-bottom: 8px;
}

.error-item .error-word {
  font-weight: 600;
  font-family: Georgia, serif;
  color: var(--color-primary);
  min-width: 120px;
}

.error-item .error-answer {
  font-size: var(--fs-sm);
  color: var(--color-danger);
}

.error-item .error-correct {
  font-size: var(--fs-sm);
  color: var(--color-success);
  font-weight: 600;
}

.error-item .error-count {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  margin-left: auto;
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
  .home-quick-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .home-hero {
    padding: 32px 16px;
  }

  .home-hero h1 {
    font-size: 1.5rem;
  }
}