/* ==========================================================================
   ㄅㄆㄇ森林鐵道學堂（AGY 獨立設計版）
   視覺主題：台灣山林鐵道・暖沙奶油底 × 森林綠 × 暖陽橘
   嚴格遵守：無 zoom、無 transform:scale、1366×650 等桌面視窗 100% 不裁切
   ========================================================================== */

:root {
  --bg-page: #F7F2E7;
  --bg-surface: #FFFDF8;
  --bg-elevated: #FFF7E2;
  --bg-accent-soft: #E7F4EE;
  --bg-warn-soft: #FFF0DC;
  --bg-danger-soft: #FDECE9;

  --forest-primary: #1B6B56;
  --forest-dark: #124B3C;
  --forest-border: #A8D5C6;

  --amber-accent: #E89223;
  --amber-bright: #FFB84D;
  --coral-accent: #D9533F;
  --sky-accent: #276BB0;
  --plum-accent: #6E4996;

  --text-main: #1F2D28;
  --text-secondary: #4A5E56;
  --text-muted: #6C7F77;

  --border-light: #DFD5C0;
  --border-strong: #C2B499;
  --shadow-card: 0 3px 10px rgba(27, 65, 52, 0.08);

  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;

  --font-sans: "Microsoft JhengHei", "PingFang TC", "Noto Sans TC", "Heiti TC", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
  background-color: var(--bg-page);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.4;
  -webkit-text-size-adjust: 100%;
}

button {
  font-family: inherit;
  cursor: pointer;
  touch-action: manipulation;
}

button:disabled {
  cursor: not-allowed;
}

button:focus-visible {
  outline: 3px solid var(--amber-accent);
  outline-offset: 2px;
}

[hidden] {
  display: none !important;
}

/* ==========================================================================
   外層主框架：桌面雙欄（左車票側欄 + 右主舞台），高度精算確保 650px 不裁切
   ========================================================================== */

.app-shell {
  display: grid;
  grid-template-columns: 238px minmax(0, 1fr);
  gap: 12px;
  max-width: 1680px;
  margin: 0 auto;
  padding: 10px 14px;
  align-items: start;
}

/* ==========================================================================
   左側導覽與車票側欄
   ========================================================================== */

.sidebar {
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 10px 11px;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.brand-header {
  display: flex;
  align-items: center;
  gap: 9px;
  padding-bottom: 7px;
  border-bottom: 2px dashed var(--border-light);
}

.mascot-badge {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.brand-title {
  margin: 0;
  font-size: 1.08rem;
  font-weight: 800;
  color: var(--forest-dark);
  letter-spacing: 0.02em;
}

.brand-subtitle {
  margin: 2px 0 0;
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.storage-alert {
  background: var(--bg-warn-soft);
  border: 1.5px solid var(--amber-accent);
  color: #7A4100;
  border-radius: var(--radius-sm);
  padding: 6px 8px;
  font-size: 0.76rem;
  font-weight: 700;
  line-height: 1.35;
}

/* 導覽按鈕列 */
.mode-nav {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: 7px;
  width: 100%;
  min-height: 38px;
  padding: 6px 9px;
  background: #F6F0E2;
  border: 1.5px solid var(--border-light);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  font-size: 0.92rem;
  font-weight: 700;
  text-align: left;
  transition: background-color 0.15s ease, border-color 0.15s ease;
}

.nav-btn:hover {
  background: #EFE5CE;
  border-color: var(--border-strong);
}

.nav-btn.is-active {
  background: var(--forest-primary);
  border-color: var(--forest-dark);
  color: #FFFFFF;
}

.nav-icon {
  font-size: 1.05rem;
  line-height: 1;
}

.nav-label {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-pill {
  font-size: 0.72rem;
  padding: 2px 6px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.75);
  color: var(--forest-dark);
  font-weight: 800;
}

.nav-btn.is-active .nav-pill {
  background: var(--amber-bright);
  color: #1F2D28;
}

/* 側欄小統計 2x2 */
.ticket-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 5px;
  background: var(--bg-elevated);
  border: 1.5px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 6px;
}

.stat-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: 6px;
  padding: 4px 6px;
  display: flex;
  flex-direction: column;
}

.stat-label {
  font-size: 0.7rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.stat-value {
  font-size: 0.88rem;
  color: var(--forest-dark);
  font-weight: 800;
}

/* 側欄快速操作 */
.sidebar-quick-actions {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  gap: 5px;
}

.quick-btn {
  min-height: 34px;
  padding: 4px 6px;
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  font-weight: 700;
  border: 1.5px solid var(--border-strong);
  background: var(--bg-surface);
  color: var(--text-main);
}

.quick-btn-review {
  background: #FFF2D6;
  border-color: var(--amber-accent);
  color: #6B3A00;
}

.quick-btn-review:hover:not(:disabled) {
  background: #FFE5B4;
}

.quick-btn-review:disabled {
  opacity: 0.55;
}

.quick-btn-ResultClear:hover {
  background: var(--bg-danger-soft);
  border-color: var(--coral-accent);
  color: #8E2314;
}

/* 側欄內嵌確認框 */
.confirm-Popover {
  background: var(--bg-danger-soft);
  border: 1.5px solid var(--coral-accent);
  border-radius: var(--radius-sm);
  padding: 7px 8px;
}

.confirm-text {
  margin: 0 0 6px;
  font-size: 0.76rem;
  font-weight: 700;
  color: #7D1E10;
}

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

.btn-danger-confirm,
.btn-cancel-confirm {
  flex: 1;
  min-height: 30px;
  padding: 4px 8px;
  border-radius: 6px;
  font-size: 0.76rem;
  font-weight: 800;
}

.btn-danger-confirm {
  background: var(--coral-accent);
  color: #FFFFFF;
  border: 1px solid #A83323;
}

.btn-cancel-confirm {
  background: #FFFFFF;
  color: var(--text-main);
  border: 1px solid var(--border-strong);
}

/* 側欄底部（100%比例必現區） */
.sidebar-footer {
  margin-top: 2px;
  padding-top: 6px;
  border-top: 1.5px dashed var(--border-light);
  font-size: 0.72rem;
  color: var(--text-secondary);
}

.footer-line {
  margin: 2px 0;
  line-height: 1.3;
}

/* ==========================================================================
   右側主工作區與單元一：37符號注音點讀
   ========================================================================== */

.workspace {
  min-width: 0;
}

.view-panel {
  width: 100%;
}

.explore-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 308px;
  gap: 12px;
  align-items: stretch;
}

.symbol-board {
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 11px 14px;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.board-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding-bottom: 6px;
  border-bottom: 1.5px solid var(--border-light);
}

.board-title {
  margin: 0;
  font-size: 1.12rem;
  font-weight: 800;
  color: var(--forest-dark);
}

.board-desc {
  margin: 2px 0 0;
  font-size: 0.78rem;
  color: var(--text-secondary);
}

.group-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.legend-chip {
  font-size: 0.74rem;
  font-weight: 800;
  padding: 3px 8px;
  border-radius: 999px;
}

.legend-initial {
  background: #E3F3ED;
  color: #145946;
}

.legend-medial {
  background: #E6F0FA;
  color: #1D558F;
}

.legend-final {
  background: #FFF0D9;
  color: #8A4F08;
}

.symbol-groups-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.symbol-group-row {
  display: grid;
  grid-template-columns: 185px minmax(0, 1fr);
  gap: 10px;
}

.symbol-group {
  background: #FAF5E8;
  border: 1.5px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 7px 9px;
}

.group-title {
  margin: 0 0 6px;
  font-size: 0.82rem;
  font-weight: 800;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 5px;
}

.group-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  display: inline-block;
}

.dot-initial { background: var(--forest-primary); }
.dot-medial { background: var(--sky-accent); }
.dot-final { background: var(--amber-accent); }

.symbol-grid {
  display: grid;
  gap: 6px;
}

.grid-initial {
  grid-template-columns: repeat(7, minmax(0, 1fr));
}

.grid-medial {
  grid-template-columns: repeat(1, minmax(0, 1fr));
}

.grid-final {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.symbol-btn {
  position: relative;
  min-height: 46px;
  padding: 4px 6px;
  border-radius: 10px;
  border: 2px solid var(--border-strong);
  background: #FFFFFF;
  color: var(--text-main);
  font-size: 1.45rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.1s ease, background-color 0.12s ease, border-color 0.12s ease;
}

.symbol-btn:hover {
  background: var(--bg-elevated);
  border-color: var(--forest-primary);
}

.symbol-btn.is-selected {
  background: var(--forest-primary);
  border-color: var(--forest-dark);
  color: #FFFFFF;
  box-shadow: 0 0 0 3px rgba(27, 107, 86, 0.22);
}

.symbol-btn.is-seen::after {
  content: "✓";
  position: absolute;
  top: 2px;
  right: 4px;
  font-size: 0.68rem;
  font-weight: 900;
  color: var(--forest-primary);
}

.symbol-btn.is-selected.is-seen::after {
  color: var(--amber-bright);
}

/* 右側點讀卡 */
.flashcard-panel {
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 12px 13px;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 8px;
}

.flashcard-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  flex-wrap: wrap;
}

.flashcard-group-tag {
  font-size: 0.78rem;
  font-weight: 800;
  padding: 3px 9px;
  border-radius: 999px;
  background: var(--bg-accent-soft);
  color: var(--forest-dark);
}

.flashcard-order {
  font-size: 0.76rem;
  color: var(--text-secondary);
  font-weight: 700;
}

.flashcard-seen-tag {
  font-size: 0.75rem;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: 999px;
  background: #F1ECE1;
  color: var(--text-secondary);
}

.flashcard-seen-tag.is-done {
  background: #DCF2E8;
  color: #125944;
}

.flashcard-hero {
  background: linear-gradient(180deg, #FFFDF7 0%, #FFF5DC 100%);
  border: 2px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 10px;
  text-align: center;
}

.flashcard-symbol {
  font-size: 4.1rem;
  font-weight: 900;
  line-height: 1.08;
  color: var(--forest-dark);
}

.flashcard-phonetic-note {
  margin-top: 4px;
  font-size: 0.78rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.flashcard-examples {
  background: #F8F3E6;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 7px 9px;
}

.examples-label {
  font-size: 0.74rem;
  color: var(--text-secondary);
  font-weight: 700;
  margin-bottom: 4px;
}

.examples-list {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.example-chip {
  font-size: 0.82rem;
  font-weight: 700;
  background: #FFFFFF;
  border: 1px solid var(--border-light);
  border-radius: 6px;
  padding: 3px 7px;
  color: var(--text-main);
}

.flashcard-controls {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.btn-play-main {
  width: 100%;
  min-height: 46px;
  padding: 8px 12px;
  border-radius: var(--radius-md);
  border: 2px solid var(--forest-dark);
  background: var(--forest-primary);
  color: #FFFFFF;
  font-size: 1.02rem;
  font-weight: 800;
}

.btn-play-main:hover {
  background: var(--forest-dark);
}

.btn-play-main.is-error {
  background: var(--coral-accent);
  border-color: #9E3020;
}

.flashcard-stepper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.btn-step {
  min-height: 36px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border-strong);
  background: #FFFFFF;
  color: var(--text-main);
  font-size: 0.85rem;
  font-weight: 700;
}

.btn-step:hover {
  background: var(--bg-elevated);
}

.flashcard-status-box {
  background: var(--bg-accent-soft);
  border: 1.5px solid var(--forest-border);
  border-radius: var(--radius-sm);
  padding: 7px 9px;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--forest-dark);
  min-height: 46px;
  display: flex;
  align-items: center;
}

.flashcard-status-box.is-error {
  background: var(--bg-danger-soft);
  border-color: var(--coral-accent);
  color: #8A1F11;
}

/* ==========================================================================
   單元二～四＆錯題重練：互動練習舞台
   ========================================================================== */

.practice-shell {
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 12px 14px;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.practice-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding-bottom: 8px;
  border-bottom: 1.5px solid var(--border-light);
  flex-wrap: wrap;
}

.practice-title-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}

.practice-mode-badge {
  background: var(--forest-primary);
  color: #FFFFFF;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 999px;
}

.practice-title {
  margin: 0;
  font-size: 1.12rem;
  font-weight: 800;
  color: var(--forest-dark);
}

.round-progress-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}

.round-counter {
  font-size: 0.88rem;
  font-weight: 800;
  color: var(--text-main);
}

.round-dots {
  display: flex;
  gap: 4px;
}

.round-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: #E2DAC7;
  border: 1px solid var(--border-strong);
}

.round-dot.is-current {
  background: var(--amber-accent);
  transform: scale(1.15);
}

.round-dot.is-done {
  background: var(--forest-primary);
}

.btn-restart-round {
  min-height: 34px;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border-strong);
  background: #FAF5E8;
  color: var(--text-main);
  font-size: 0.8rem;
  font-weight: 700;
}

.practice-stage {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 12px;
  align-items: stretch;
}

/* 左欄：題目提示卡 */
.question-card {
  background: linear-gradient(180deg, #FFFDF9 0%, #FAF3E1 100%);
  border: 2px solid var(--border-strong);
  border-radius: var(--radius-md);
  padding: 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 8px;
}

.question-type-tag {
  font-size: 0.76rem;
  font-weight: 800;
  padding: 3px 10px;
  border-radius: 999px;
  background: #EFE6D0;
  color: var(--text-secondary);
}

.prompt-listen-box,
.prompt-visual-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 100%;
}

.btn-listen-audio {
  width: 100%;
  max-width: 250px;
  min-height: 48px;
  padding: 8px 14px;
  border-radius: var(--radius-md);
  border: 2px solid var(--forest-dark);
  background: var(--forest-primary);
  color: #FFFFFF;
  font-size: 1.05rem;
  font-weight: 800;
}

.btn-listen-audio:hover {
  background: var(--forest-dark);
}

.btn-listen-audio.is-error {
  background: var(--coral-accent);
  border-color: #9C2B1B;
}

.listen-lock-hint {
  margin: 0;
  padding: 7px 10px;
  border-radius: var(--radius-sm);
  background: var(--bg-warn-soft);
  border: 1.5px solid var(--amber-accent);
  color: #6E3B00;
  font-size: 0.82rem;
  font-weight: 700;
  width: 100%;
}

.listen-lock-hint.is-ready {
  background: var(--bg-accent-soft);
  border-color: var(--forest-primary);
  color: var(--forest-dark);
}

.listen-lock-hint.is-error {
  background: var(--bg-danger-soft);
  border-color: var(--coral-accent);
  color: #8A1F11;
}

.visual-emoji {
  font-size: 3.4rem;
  line-height: 1.1;
}

.visual-word-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.visual-word {
  font-size: 2.3rem;
  font-weight: 900;
  color: var(--text-main);
}

.visual-notation {
  font-size: 2.6rem;
  font-weight: 900;
  color: var(--forest-dark);
  background: #FFFFFF;
  border: 2px solid var(--forest-primary);
  border-radius: var(--radius-sm);
  padding: 2px 12px;
  letter-spacing: 0.04em;
}

.visual-hint {
  margin: 0;
  font-size: 1rem;
  font-weight: 800;
  color: var(--text-secondary);
}

.visual-rule-note {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--forest-dark);
  background: var(--bg-accent-soft);
  border: 1px solid var(--forest-border);
  border-radius: var(--radius-sm);
  padding: 5px 9px;
  width: 100%;
}

/* 右欄：作答與回饋區 */
.answer-panel {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 10px;
}

.answer-work-area {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* 拼音組合槽 */
.spell-composer {
  background: #FAF5E8;
  border: 2px solid var(--border-strong);
  border-radius: var(--radius-md);
  padding: 9px 11px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  flex-wrap: wrap;
}

.spell-slots-wrap {
  display: flex;
  align-items: center;
  gap: 7px;
  flex-wrap: wrap;
}

.spell-slots-label {
  font-size: 0.85rem;
  font-weight: 800;
  color: var(--text-secondary);
}

.spell-slots {
  display: flex;
  gap: 6px;
}

.spell-slot {
  width: 50px;
  height: 50px;
  border-radius: 10px;
  border: 2px dashed var(--border-strong);
  background: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.7rem;
  font-weight: 900;
  color: var(--forest-dark);
}

.spell-slot.is-filled {
  border-style: solid;
  border-color: var(--forest-primary);
  background: var(--bg-accent-soft);
}

.spell-given-tone {
  font-size: 0.85rem;
  font-weight: 800;
  padding: 5px 9px;
  border-radius: var(--radius-sm);
  background: #FFF0D9;
  border: 1.5px solid var(--amber-accent);
  color: #7A4300;
}

.spell-action-btns {
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-spell-tool {
  min-height: 42px;
  padding: 6px 11px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border-strong);
  background: #FFFFFF;
  color: var(--text-main);
  font-size: 0.88rem;
  font-weight: 800;
}

.btn-spell-tool:hover:not(:disabled) {
  background: var(--bg-elevated);
}

.btn-spell-submit {
  min-height: 42px;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  border: 2px solid var(--forest-dark);
  background: var(--forest-primary);
  color: #FFFFFF;
  font-size: 0.92rem;
  font-weight: 800;
}

.btn-spell-submit:hover:not(:disabled) {
  background: var(--forest-dark);
}

/* 選項網格 */
.choices-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 9px;
}

.choices-grid.is-spell-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.choices-grid.is-tone-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.choice-btn {
  min-height: 76px;
  padding: 8px 10px;
  border-radius: var(--radius-md);
  border: 2px solid var(--border-strong);
  background: #FFFFFF;
  color: var(--text-main);
  font-size: 2rem;
  font-weight: 900;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  transition: background-color 0.12s ease, border-color 0.12s ease;
}

.choice-btn:hover:not(:disabled) {
  background: var(--bg-elevated);
  border-color: var(--forest-primary);
}

.choice-btn:disabled {
  opacity: 0.55;
  background: #EFECE4;
}

.choice-btn.is-correct {
  background: #D8F3E5;
  border-color: var(--forest-primary);
  color: var(--forest-dark);
  opacity: 1;
}

.choice-btn.is-wrong {
  background: var(--bg-danger-soft);
  border-color: var(--coral-accent);
  color: #8A1F11;
}

.choice-btn.is-picked {
  background: var(--bg-accent-soft);
  border-color: var(--forest-primary);
}

.choice-sub {
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--text-secondary);
}

/* 底部回饋與「下一題」按鈕列 */
.practice-footer-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  background: #FAF5E8;
  border: 2px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 8px 11px;
}

.feedback-banner {
  flex: 1;
  font-size: 0.9rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.35;
}

.feedback-banner.is-ok {
  color: var(--forest-dark);
}

.feedback-banner.is-retry {
  color: #8A3800;
}

.btn-next-question {
  flex-shrink: 0;
  min-width: 148px;
  min-height: 46px;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  border: 2px solid #9E6208;
  background: var(--amber-bright);
  color: #1F2D28;
  font-size: 1rem;
  font-weight: 900;
}

.btn-next-question:hover:not(:disabled) {
  background: #FFA726;
}

.btn-next-question:disabled {
  background: #E5DEC9;
  border-color: var(--border-strong);
  color: var(--text-muted);
}

/* ==========================================================================
   單元五：學習成果與錯題本
   ========================================================================== */

.results-shell {
  background: var(--bg-surface);
  border: 2px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 12px 14px;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding-bottom: 8px;
  border-bottom: 1.5px solid var(--border-light);
  flex-wrap: wrap;
}

.results-title {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--forest-dark);
}

.results-subtitle {
  margin: 2px 0 0;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.results-header-btns {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.btn-start-review {
  min-height: 40px;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  border: 2px solid var(--forest-dark);
  background: var(--forest-primary);
  color: #FFFFFF;
  font-size: 0.88rem;
  font-weight: 800;
}

.btn-start-review:disabled {
  opacity: 0.55;
}

.btn-clear-progress {
  min-height: 40px;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--coral-accent);
  background: #FFFFFF;
  color: #962717;
  font-size: 0.85rem;
  font-weight: 800;
}

.round-celebration {
  background: #FFF3D1;
  border: 2px solid var(--amber-accent);
  border-radius: var(--radius-md);
  padding: 8px 12px;
  font-size: 0.92rem;
  font-weight: 800;
  color: #6B3A00;
}

.confirm-banner {
  background: var(--bg-danger-soft);
  border: 2px solid var(--coral-accent);
  border-radius: var(--radius-md);
  padding: 9px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}

.confirm-banner-text {
  margin: 0;
  font-size: 0.86rem;
  font-weight: 800;
  color: #7D1E10;
}

.confirm-banner-btns {
  display: flex;
  gap: 8px;
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
}

.metric-card {
  background: #FAF5E8;
  border: 1.5px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 9px 10px;
  display: flex;
  align-items: center;
  gap: 9px;
}

.metric-icon {
  font-size: 1.7rem;
  line-height: 1;
}

.metric-info {
  display: flex;
  flex-direction: column;
}

.metric-name {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 700;
}

.metric-number {
  font-size: 1.15rem;
  font-weight: 900;
  color: var(--forest-dark);
}

.metric-note {
  font-size: 0.7rem;
  color: var(--text-muted);
}

.results-bottom-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 10px;
}

.wrong-list-panel,
.seen-panel {
  background: #FAF5E8;
  border: 1.5px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 9px 11px;
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.panel-subhead {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px;
  flex-wrap: wrap;
}

.panel-subhead h3 {
  margin: 0;
  font-size: 0.92rem;
  font-weight: 800;
  color: var(--forest-dark);
}

.subhead-note {
  font-size: 0.72rem;
  color: var(--text-secondary);
}

.wrong-items-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  min-height: 44px;
  align-content: flex-start;
}

.wrong-chip {
  background: #FFFFFF;
  border: 1.5px solid var(--coral-accent);
  border-radius: 8px;
  padding: 4px 8px;
  font-size: 0.8rem;
  font-weight: 800;
  color: #7D1E10;
}

.empty-wrong-msg {
  margin: 0;
  font-size: 0.84rem;
  font-weight: 700;
  color: var(--forest-dark);
}

.mini-symbols-wall {
  display: grid;
  grid-template-columns: repeat(13, minmax(0, 1fr));
  gap: 4px;
}

.mini-sym {
  height: 26px;
  border-radius: 5px;
  background: #FFFFFF;
  border: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.82rem;
  font-weight: 800;
  color: var(--text-muted);
}

.mini-sym.is-seen {
  background: #D8F3E5;
  border-color: var(--forest-primary);
  color: var(--forest-dark);
}

.results-quick-start {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-top: 2px;
}

.btn-quick-mode {
  flex: 1;
  min-height: 36px;
  padding: 5px 8px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border-strong);
  background: #FFFFFF;
  color: var(--text-main);
  font-size: 0.8rem;
  font-weight: 800;
}

.btn-quick-mode:hover {
  background: var(--bg-elevated);
}

/* ==========================================================================
   平板與手機響應式設定（768×1024 與 390×844 自然垂直捲動、零水平溢出）
   ========================================================================== */

@media (max-width: 1023px) {
  .app-shell {
    grid-template-columns: 1fr;
    padding: 10px;
  }

  .mode-nav {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
  }

  .explore-layout {
    grid-template-columns: 1fr;
  }

  .symbol-group-row {
    grid-template-columns: 1fr;
  }

  .grid-medial {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .practice-stage {
    grid-template-columns: 1fr;
  }

  .metrics-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .results-bottom-grid {
    grid-template-columns: 1fr;
  }

  .mini-symbols-wall {
    grid-template-columns: repeat(10, minmax(0, 1fr));
  }
}

@media (max-width: 600px) {
  .app-shell {
    padding: 8px;
    gap: 10px;
  }

  .mode-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .grid-initial {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .grid-final {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .choices-grid.is-spell-grid,
  .choices-grid.is-tone-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .practice-footer-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .btn-next-question {
    width: 100%;
  }

  .mini-symbols-wall {
    grid-template-columns: repeat(8, minmax(0, 1fr));
  }
}

/* 尊重系統減少動態效果設定 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}