/* ============================================================
   MODULE: Nhớ Chữ Hán — chỉ dùng biến từ tokens.css
   ============================================================ */

.hz-tabs {
  display: flex;
  gap: var(--space-2);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-4);
  overflow-x: auto;
}
.hz-tab {
  padding: var(--space-2) var(--space-3);
  border: none;
  background: none;
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  cursor: pointer;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
}
.hz-tab.is-active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: 600;
}
.hz-panel { display: none; }
.hz-panel.is-active { display: block; }
.hz-tab--link { text-decoration: none; display: inline-block; color: var(--color-secondary); }
.hz-tab--link:hover { text-decoration: underline; }

/* --- Flashcard (thiết kế lại: to hơn, có pinyin + nút phát âm) --- */
.hz-flashcard-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
}
.hz-flashcard {
  width: 340px;
  height: 260px;
  perspective: 1200px;
  cursor: pointer;
}
.hz-flashcard__inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.5s;
  transform-style: preserve-3d;
}
.hz-flashcard.is-flipped .hz-flashcard__inner { transform: rotateY(180deg); }
.hz-flashcard__face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: linear-gradient(135deg, var(--color-surface), var(--color-surface-alt));
  box-shadow: var(--shadow-3);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  text-align: center;
  padding: var(--space-4);
}
.hz-flashcard__face--back { transform: rotateY(180deg); }
.hz-flashcard__hanzi { font-size: 5.5rem; line-height: 1; color: var(--color-text); font-family: var(--font-family-display), "Noto Sans SC", sans-serif; }
.hz-flashcard__hanzi-pinyin { color: var(--color-primary); font-weight: 700; font-size: var(--text-h4); margin-top: 2px; }
.hz-flashcard__pinyin { color: var(--color-secondary); font-size: var(--font-size-lg); }
.hz-flashcard__meaning { color: var(--color-text); font-size: var(--text-h3); font-weight: 700; }
.hz-flashcard__level { color: var(--color-text-muted); font-size: var(--font-size-sm); margin-top: var(--space-1); }

.hz-flashcard-controls {
  display: flex;
  gap: var(--space-2);
  align-items: center;
}
.hz-btn {
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  padding: var(--space-2) var(--space-3);
  cursor: pointer;
  font-size: var(--font-size-sm);
  color: var(--color-text);
}
.hz-btn:hover { background: var(--color-surface-alt); }
.hz-btn.is-active { background: var(--color-primary); border-color: var(--color-primary); color: var(--color-text-on-primary); }

/* --- Nút phát âm (Web Speech API — dùng ở Flashcard, Chiết tự, Bộ thủ) --- */
.hz-speak-btn {
  position: absolute; top: var(--space-2); right: var(--space-2);
  width: 32px; height: 32px; border-radius: 50%;
  border: 1px solid var(--color-border); background: var(--color-surface);
  cursor: pointer; font-size: 0.9rem; display: flex; align-items: center; justify-content: center;
  transition: transform var(--duration-fast) var(--ease-standard);
}
.hz-speak-btn:hover { transform: scale(1.1); border-color: var(--color-primary); }
.hz-speak-btn--lg { position: static; width: 40px; height: 40px; font-size: 1.1rem; flex-shrink: 0; }

.nv-cross-banner {
  display: block;
  background: linear-gradient(135deg, var(--color-secondary), #6fa9b8);
  color: var(--color-text-on-primary);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  margin-bottom: var(--space-3);
  font-size: var(--font-size-sm);
}
.nv-cross-banner:hover { text-decoration: none; opacity: 0.95; }
.hz-progress { color: var(--color-text-muted); font-size: var(--font-size-sm); }

/* --- Bộ thủ: nhóm theo số nét --- */
.hz-search {
  width: 100%;
  max-width: 320px;
  padding: var(--space-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-3);
  font-size: var(--font-size-base);
}
.hz-radical-grid { display: flex; flex-direction: column; gap: var(--space-4); }
.hz-radical-group__title {
  font-family: var(--font-family-display); font-weight: 700; font-size: var(--text-h4);
  color: var(--color-text); margin-bottom: var(--space-2);
  padding-bottom: var(--space-1); border-bottom: 2px solid var(--color-border);
}
.hz-radical-group__count { color: var(--color-text-muted); font-weight: 400; font-size: var(--text-body-sm); font-family: var(--font-family-mono); }
.hz-radical-group__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
  gap: var(--space-2);
}
.hz-radical-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  text-align: center;
  padding: var(--space-2);
  cursor: pointer;
  font-family: inherit;
  transition: transform var(--duration-fast) var(--ease-standard), box-shadow var(--duration-fast) var(--ease-standard);
}
.hz-radical-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-2); border-color: var(--color-primary); }
.hz-radical-card__glyph { font-size: 1.75rem; font-family: var(--font-family-display), "Noto Sans SC", sans-serif; }
.hz-radical-card__meaning { font-size: var(--font-size-sm); color: var(--color-text-muted); }
.hz-radical-card__strokes { font-size: 0.75rem; color: var(--color-primary); font-weight: 600; }

/* --- Bộ lọc cấp độ HSK (dùng chung cho Flashcard + Chiết tự) --- */
.hz-level-filter {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  margin-bottom: var(--space-3);
}
.hz-level-btn {
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: 999px;
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
}
.hz-level-btn.is-active { background: var(--color-secondary); border-color: var(--color-secondary); color: var(--color-text-on-primary); }

/* --- Chiết tự: lưới chọn chữ, thiết kế lại đẹp hơn, đủ thông tin để lướt nhanh --- */
.hz-etym-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: var(--space-3);
}
.hz-etym-chip {
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-3);
  text-align: center;
  cursor: pointer;
  box-shadow: var(--shadow-1);
  transition: transform var(--duration-fast) var(--ease-standard), box-shadow var(--duration-fast) var(--ease-standard), border-color var(--duration-fast) var(--ease-standard);
}
.hz-etym-chip:hover { border-color: var(--color-primary); transform: translateY(-3px); box-shadow: var(--shadow-3); }
.hz-etym-chip__glyph { font-size: 2.2rem; line-height: 1.2; font-family: var(--font-family-display), "Noto Sans SC", sans-serif; color: var(--color-text); }
.hz-etym-chip__pinyin { font-size: var(--text-body-sm); color: var(--color-primary); font-weight: 700; margin-top: 2px; }
.hz-etym-chip__meaning { font-size: var(--text-caption); color: var(--color-text-muted); margin-top: 2px; min-height: 15px; }
.hz-etym-chip__cta { font-size: var(--text-caption); color: var(--color-secondary); font-weight: 600; margin-top: var(--space-2); }

/* --- Chiết tự: panel chi tiết --- */
.hz-etym-detail {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  position: relative;
}
.hz-etym-detail__head {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4);
  background: linear-gradient(135deg, var(--color-surface-alt), var(--color-surface));
  border-bottom: 1px solid var(--color-border);
}
.hz-etym-detail__glyph-wrap { position: relative; display: flex; flex-direction: column; align-items: center; gap: var(--space-2); }
.hz-etym-detail__glyph {
  font-size: 4.5rem;
  line-height: 1;
  color: var(--color-primary);
  font-family: var(--font-family-display), "Noto Sans SC", sans-serif;
}
.hz-etym-detail__pinyin { font-size: var(--font-size-lg); color: var(--color-secondary); font-weight: 600; }
.hz-etym-detail__meaning { font-size: var(--font-size-lg); font-weight: 700; margin: var(--space-1) 0; }
.hz-etym-detail__badges { display: flex; gap: var(--space-2); flex-wrap: wrap; }
.hz-etym-badge {
  font-size: 0.7rem; font-weight: 600; padding: 2px var(--space-2); border-radius: 999px;
  background: var(--color-surface); border: 1px solid var(--color-border); color: var(--color-text-muted);
}
.hz-etym-badge--trad { color: var(--color-secondary); border-color: var(--color-secondary); font-family: var(--font-family-display), "Noto Sans SC", sans-serif; }
.hz-etym-badge--synonym { color: var(--color-success); border-color: var(--color-success); background: var(--color-success-bg); }
.hz-etym-badge--antonym { color: var(--color-error); border-color: var(--color-error); background: var(--color-error-bg); }
.hz-etym-detail__body { padding: var(--space-4); }
.hz-etym-section { margin-bottom: var(--space-4); }
.hz-etym-section:last-child { margin-bottom: 0; }
.hz-etym-section__title {
  display: flex; align-items: center; gap: var(--space-2);
  font-size: var(--font-size-base); font-weight: 700; color: var(--color-text);
  margin-bottom: var(--space-2);
}
.hz-etym-section__icon {
  width: 28px; height: 28px; border-radius: 50%;
  background: var(--color-surface-alt);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.9rem;
}
.hz-etym-parts { list-style: none; padding: 0; margin: 0 0 var(--space-2); display: flex; flex-direction: column; gap: var(--space-1); }
.hz-etym-parts li {
  display: flex; gap: var(--space-2); align-items: baseline;
  background: var(--color-surface-alt); border-radius: var(--radius-sm); padding: var(--space-2);
  font-size: var(--font-size-sm); color: var(--color-text-muted);
}
.hz-etym-parts li strong { color: var(--color-primary); font-size: var(--font-size-lg); }
.hz-etym-story { color: var(--color-text); font-size: var(--font-size-sm); line-height: 1.7; }
.hz-etym-mnemonic-box {
  background: linear-gradient(135deg, rgba(192,57,43,0.06), rgba(44,95,111,0.06));
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-sm);
  padding: var(--space-3);
  font-size: var(--font-size-sm);
  color: var(--color-text);
  line-height: 1.7;
}

/* --- Các phương pháp ghi nhớ (nhiều cách, không chỉ 1) --- */
.hz-etym-methods { display: flex; flex-direction: column; gap: var(--space-2); }
.hz-etym-method {
  background: var(--color-surface-alt); border-left: 3px solid var(--color-primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0; padding: var(--space-2) var(--space-3);
}
.hz-etym-method__label { font-weight: 700; font-size: var(--text-body-sm); color: var(--color-primary); margin-bottom: 2px; }
.hz-etym-method__text { margin: 0; font-size: var(--font-size-sm); color: var(--color-text); line-height: 1.6; }

/* --- Đồng nghĩa / Trái nghĩa --- */
.hz-etym-relations { font-size: var(--font-size-sm); }
.hz-etym-relations__label { font-weight: 600; color: var(--color-text-muted); margin-right: var(--space-2); }
.hz-etym-compounds { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.hz-etym-compound-chip {
  background: var(--color-surface-alt);
  border-radius: var(--radius-sm);
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-sm);
}
.hz-etym-compound-chip strong { color: var(--color-secondary); font-size: var(--font-size-base); }
.hz-etym-compound-chip em { color: var(--color-text-muted); font-style: normal; }

/* --- Viết chữ --- */
.hz-write-wrap { display: flex; gap: var(--space-4); flex-wrap: wrap; align-items: flex-start; }
.hz-canvas {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  touch-action: none;
  cursor: crosshair;
}

/* --- SRS --- */
.hz-srs-summary {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}
.hz-srs-stat { text-align: center; }
.hz-srs-stat__num { font-size: var(--font-size-2xl); color: var(--color-primary); font-weight: 700; }
.hz-srs-stat__label { color: var(--color-text-muted); font-size: var(--font-size-sm); }

/* --- Thống kê --- */
.hz-bar-chart { display: flex; align-items: flex-end; gap: var(--space-2); height: 140px; }
.hz-bar { flex: 1; background: var(--color-secondary); border-radius: 4px 4px 0 0; position: relative; }
.hz-bar__label {
  position: absolute; bottom: -20px; left: 0; right: 0; text-align: center;
  font-size: 0.7rem; color: var(--color-text-muted);
}