/* 九九乘法表練習 - RWD 響應式設計 (Mobile-First) */

/* === CSS 變數定義 === */
:root {
    /* 顏色主題 - 兒童友善 */
    --primary-color: #4285f4;
    --success-color: #34a853;
    --error-color: #ea4335;
    --warning-color: #fbbc04;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #202124;
    --text-secondary: #5f6368;
    --border-color: #dadce0;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);

    /* 字體大小（流體排版） */
    --font-size-title: clamp(1.5rem, 4vw, 2rem);
    --font-size-question: clamp(1.8rem, 5vw, 2.5rem);
    --font-size-input: clamp(1.5rem, 4vw, 2rem);
    --font-size-button: clamp(1.2rem, 3vw, 1.5rem);
    --font-size-progress: clamp(1rem, 2.5vw, 1.2rem);

    /* 間距系統 */
    --spacing-xs: 0.5rem;
    --spacing-s: 1rem;
    --spacing-m: 1.5rem;
    --spacing-l: 2rem;
    --spacing-xl: 3rem;

    /* 觸控目標大小 */
    --touch-target: 44px;
    --touch-target-large: 60px;

    /* 容器寬度 */
    --container-max: 768px;
}

/* === 基礎重置 === */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'PingFang TC', 'Noto Sans CJK TC', 'Microsoft JhengHei', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: none;
}

/* === 主容器（基礎：手機） === */
.app-container {
    min-height: calc(var(--vh, 1vh) * 100);
    display: flex;
    flex-direction: column;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--spacing-s);
}

/* === 開始設定頁面 === */
.start-screen {
    height: calc(var(--vh, 1vh) * 100);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-l);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    background: var(--bg-color);
}

.start-content {
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: var(--shadow);
    padding: var(--spacing-xl);
    text-align: center;
    max-width: 90%;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    margin: auto;
}

.start-title {
    font-size: var(--font-size-title);
    color: var(--primary-color);
    margin-bottom: var(--spacing-s);
    font-weight: 600;
}

.start-subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: var(--spacing-l);
}

/* 設定區域 */
.settings-section {
    text-align: left;
    margin-bottom: var(--spacing-l);
}

.setting-item {
    margin-bottom: var(--spacing-m);
    padding: var(--spacing-m);
    background: rgba(66, 133, 244, 0.05);
    border-radius: 12px;
}

.setting-label {
    font-size: var(--font-size-progress);
    font-weight: 500;
    color: var(--text-color);
    display: flex;
    align-items: center;
    cursor: pointer;
    min-height: var(--touch-target);
}

.setting-desc {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
    font-style: italic;
}

/* 自訂 Checkbox 和 Radio */
.setting-checkbox,
.setting-radio {
    display: none;
}

.checkmark,
.radio-mark {
    width: 20px;
    height: 20px;
    border: 2px solid var(--primary-color);
    margin-right: var(--spacing-s);
    position: relative;
    display: inline-block;
}

.checkmark {
    border-radius: 4px;
}

.radio-mark {
    border-radius: 50%;
}

.setting-checkbox:checked + .checkmark {
    background: var(--primary-color);
}

.setting-checkbox:checked + .checkmark::after {
    content: '✓';
    color: white;
    position: absolute;
    top: -2px;
    left: 2px;
    font-size: 14px;
    font-weight: bold;
}

.setting-radio:checked + .radio-mark {
    background: var(--primary-color);
}

.setting-radio:checked + .radio-mark::after {
    content: '';
    width: 8px;
    height: 8px;
    background: white;
    border-radius: 50%;
    position: absolute;
    top: 3px;
    left: 3px;
}

/* Radio Group */
.radio-group {
    margin-top: var(--spacing-s);
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-s);
    justify-content: center;
}

.radio-label {
    font-size: 0.9rem;
    font-weight: normal;
    cursor: pointer;
    min-height: var(--touch-target);
    display: flex;
    align-items: center;
    flex: 1 1 auto;
    min-width: 80px;
    justify-content: center;
}

/* 練習模式子選單 */
.practice-mode-options {
    margin-top: var(--spacing-m);
    padding: var(--spacing-m);
    background: rgba(66, 133, 244, 0.05);
    border-radius: 12px;
    border: 1px solid rgba(66, 133, 244, 0.2);
}

.practice-type-group {
    margin-top: var(--spacing-s);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-s);
}

.number-selection {
    margin-top: var(--spacing-m);
    padding-top: var(--spacing-m);
    border-top: 1px solid var(--border-color);
}

.number-checkboxes {
    margin-top: var(--spacing-s);
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-s);
}

/* Checkbox 樣式 */
.checkbox-label {
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 0.9rem;
    min-height: var(--touch-target);
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.2s ease;
    -webkit-tap-highlight-color: transparent;
}

.checkbox-label:hover {
    border-color: var(--primary-color);
    background: rgba(66, 133, 244, 0.05);
}

.number-checkbox {
    display: none;
}

.checkbox-mark {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--text-color);
    transition: all 0.2s ease;
}

.number-checkbox:checked + .checkbox-mark {
    color: white;
}

.number-checkbox:checked ~ .checkbox-mark,
.checkbox-label:has(.number-checkbox:checked) {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.checkbox-label:has(.number-checkbox:checked) .checkbox-mark {
    color: white;
}

/* 按鈕樣式 */
.start-btn,
.leaderboard-btn,
.voice-errors-btn,
.back-btn,
.restart-btn {
    border: none;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: var(--touch-target);
    text-align: center;
    -webkit-tap-highlight-color: transparent;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    touch-action: manipulation;
    margin-bottom: var(--spacing-s);
}

.start-btn {
    background: var(--primary-color);
    color: white;
    padding: var(--spacing-m) var(--spacing-l);
    font-size: var(--font-size-progress);
    width: 100%;
}

/* 設定按鈕 */
.settings-toggle-btn {
    background: var(--border-color);
    color: var(--text-color);
    padding: var(--spacing-xs) var(--spacing-s);
    font-size: 0.9rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-bottom: var(--spacing-m);
    align-self: flex-start;
}

.settings-toggle-btn:hover {
    background: var(--text-secondary);
    color: white;
}

/* 排行榜按鈕 - 使用藍色系 */
.leaderboard-btn {
    background: #4a90e2;
    color: white;
    padding: var(--spacing-s) var(--spacing-m);
    font-size: 1rem;
    width: 100%;
}

.leaderboard-btn:hover {
    background: #357abd;
    transform: translateY(-1px);
}

/* 語音錯誤記錄按鈕 - 使用灰色系 */
.voice-errors-btn {
    background: var(--text-secondary);
    color: white;
    padding: var(--spacing-s) var(--spacing-m);
    font-size: 1rem;
    width: 100%;
}

.voice-errors-btn:hover {
    background: #4a4a4a;
    transform: translateY(-1px);
}

.back-btn {
    background: var(--text-secondary);
    color: white;
    padding: var(--spacing-s) var(--spacing-m);
    font-size: 1rem;
    width: 100%;
}

.start-btn:hover,
.start-btn:active {
    background: #3367d6;
    transform: translateY(-1px);
}

.back-btn:hover {
    background: #4a4a4a;
    transform: translateY(-1px);
}

/* 設定區域 */
.settings-section {
    width: 100%;
    margin-bottom: var(--spacing-m);
    padding: var(--spacing-m);
    background: rgba(0, 0, 0, 0.05);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.settings-section[style*="display: none"] {
    opacity: 0;
    transform: translateY(-10px);
}

/* === 歷史記錄頁面 === */
.records-screen {
    height: calc(var(--vh, 1vh) * 100);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-l);
    overflow: hidden;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    background: var(--bg-color);
}

.records-content {
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: var(--shadow);
    padding: var(--spacing-l);
    max-width: 95%;
    width: 100%;
    max-height: 85vh;
    overflow-y: auto;
}

.records-title {
    font-size: var(--font-size-title);
    color: var(--primary-color);
    margin-bottom: var(--spacing-m);
    text-align: center;
    font-weight: 600;
}

/* 排行榜標籤 */
.leaderboard-tabs {
    display: flex;
    gap: 0;
    margin: var(--spacing-m) 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.leaderboard-tab {
    flex: 1;
    padding: var(--spacing-s) var(--spacing-m);
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-right: none;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s ease;
    min-height: var(--touch-target);
    display: flex;
    align-items: center;
    justify-content: center;
}

.leaderboard-tab:last-child {
    border-right: 1px solid var(--border-color);
}

.leaderboard-tab:hover {
    background: rgba(255, 87, 51, 0.05);
    color: var(--text-color);
}

.leaderboard-tab.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* 排行榜項目 */
.leaderboard-item {
    display: flex;
    align-items: center;
    padding: var(--spacing-s);
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    margin-bottom: var(--spacing-xs);
    transition: all 0.3s ease;
}

.rank-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 50px;
    margin-right: var(--spacing-s);
}

.rank-number {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--text-color);
    line-height: 1;
}

.rank-icon {
    font-size: 1.4rem;
    margin-top: 2px;
}

/* 前三名特殊樣式 */
.leaderboard-item.rank-1 {
    background: linear-gradient(135deg, #fff9c4, #fefce8);
    border: 2px solid #fbbf24;
    box-shadow: 0 2px 8px rgba(251, 191, 36, 0.3);
}

.leaderboard-item.rank-2 {
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
    border: 2px solid #64748b;
    box-shadow: 0 2px 8px rgba(100, 116, 139, 0.2);
}

.leaderboard-item.rank-3 {
    background: linear-gradient(135deg, #fef3e2, #fed7aa);
    border: 2px solid #f59e0b;
    box-shadow: 0 2px 8px rgba(245, 158, 11, 0.2);
}

.leaderboard-item .record-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.leaderboard-item .record-datetime {
    font-size: 0.85rem;
    color: var(--text-color);
    font-weight: 600;
}

.leaderboard-item .record-details {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.leaderboard-item .record-time {
    text-align: right;
    font-size: 1rem;
    font-weight: bold;
    color: var(--primary-color);
    min-width: 60px;
}

/* === 練習容器 === */
.practice-container {
    display: flex;
    flex-direction: column;
    height: calc(var(--vh, 1vh) * 100);
    gap: var(--spacing-s);
}

/* 標頭區域 */
.header {
    background: var(--card-bg);
    padding: var(--spacing-m);
    border-radius: 16px;
    box-shadow: var(--shadow);
    text-align: center;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.exit-btn {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(234, 67, 53, 0.1);
    color: var(--error-color);
    border: 2px solid var(--error-color);
    border-radius: 50%;
    width: 36px;
    height: 36px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.exit-btn:hover,
.exit-btn:active {
    background: var(--error-color);
    color: white;
    transform: translateY(-50%) scale(1.1);
}

.title-section {
    flex: 1;
}

.title {
    font-size: var(--font-size-title);
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.timer-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
}

.timer-label {
    font-size: var(--font-size-progress);
    color: var(--text-secondary);
}

.timer {
    font-size: var(--font-size-progress);
    font-weight: 600;
    color: var(--primary-color);
    font-family: 'SF Mono', 'Monaco', monospace;
}

/* 進度條 */
.progress-container {
    background: var(--card-bg);
    padding: var(--spacing-m);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.progress-bar {
    width: 100%;
    height: 6px;
    background-color: var(--border-color);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: var(--spacing-s);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    border-radius: 3px;
    transition: width 0.3s ease;
    width: 2%;
}

.progress-text {
    text-align: center;
    font-size: var(--font-size-progress);
    font-weight: 500;
    color: var(--text-secondary);
}

/* 題目區域 */
.question-container {
    flex: 1;
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: var(--shadow);
    padding: var(--spacing-l);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-m);
    text-align: center;
    min-height: 250px;
}

.question {
    font-size: var(--font-size-question);
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: var(--spacing-s);
}

.answer-blank {
    color: var(--primary-color);
    border-bottom: 3px solid var(--primary-color);
    padding: 0 var(--spacing-s);
    display: inline-block;
    min-width: 50px;
}

/* 回饋訊息 */
.feedback {
    font-size: 1.5rem;
    font-weight: 600;
    text-align: center;
    padding: var(--spacing-s);
    border-radius: 12px;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.feedback.correct {
    background-color: rgba(52, 168, 83, 0.1);
    color: var(--success-color);
    border: 2px solid var(--success-color);
    animation: bounce 0.6s ease;
}

.feedback.incorrect {
    background-color: rgba(234, 67, 53, 0.1);
    color: var(--error-color);
    border: 2px solid var(--error-color);
}

/* 答案輸入區 */
.answer-container {
    display: flex;
    gap: var(--spacing-xs);
    align-items: center;
    justify-content: center;
    width: 100%;
    max-width: 100%;
    padding: 0 var(--spacing-s);
}

.answer-input {
    flex: 1;
    min-width: 0;
    max-width: 150px;
    font-size: var(--font-size-input);
    padding: var(--spacing-s);
    border: 3px solid var(--border-color);
    border-radius: 12px;
    text-align: center;
    font-weight: 600;
    background: #ffffff;
    color: var(--text-color);
    caret-color: var(--primary-color);
    min-height: var(--touch-target);
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

.answer-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(66, 133, 244, 0.2);
}

.submit-btn {
    flex-shrink: 0;
    font-size: var(--font-size-button);
    padding: var(--spacing-s) var(--spacing-m);
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: var(--touch-target);
    min-height: var(--touch-target);
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

.submit-btn:hover,
.submit-btn:active {
    background: #3367d6;
    transform: translateY(-1px);
}

/* 答案提示 */
.answer-hint {
    margin-top: var(--spacing-s);
    text-align: center;
}

.answer-hint .hint {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin: 0;
    font-style: italic;
}

/* === 語音輸入按鈕樣式 === */
.mic-input-btn {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    border: none;
    border-radius: 50%;
    background: var(--primary-color);
    color: white;
    font-size: 1.3rem;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    transition: all 0.3s ease;
}

.mic-input-btn:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

.mic-input-btn.listening {
    background: var(--danger-color);
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0% {
        box-shadow: 0 0 0 0 rgba(229, 62, 62, 0.7);
    }
    70% {
        box-shadow: 0 0 0 20px rgba(229, 62, 62, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(229, 62, 62, 0);
    }
}

/* === 輸入模式樣式控制 === */
.input-mode-keyboard .mic-input-btn {
    display: none !important;
}

.input-mode-voice .number-pad {
    display: none !important;
}

.input-mode-both .mic-input-btn {
    display: inline-block !important;
}

.input-mode-both .number-pad {
    display: flex !important;
}

/* 虛擬數字鍵盤 - 基礎樣式（手機預設顯示） */
.number-pad {
    background: var(--card-bg);
    border-radius: 16px;
    box-shadow: var(--shadow);
    padding: var(--spacing-m);
    gap: var(--spacing-s);
    display: flex;
    flex-direction: column;
}

.number-row {
    display: flex;
    gap: var(--spacing-s);
    justify-content: center;
}

.number-btn {
    width: var(--touch-target-large);
    height: var(--touch-target-large);
    font-size: var(--font-size-button);
    font-weight: 600;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    background: #ffffff;
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.2s ease;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

.number-btn:hover,
.number-btn:active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-1px);
}

.clear-btn {
    background: rgba(234, 67, 53, 0.1);
    color: var(--error-color);
    border-color: var(--error-color);
}

.backspace-btn {
    background: rgba(251, 188, 4, 0.1);
    color: var(--warning-color);
    border-color: var(--warning-color);
}

/* 操作提示 */
.hint-container {
    text-align: center;
    padding: var(--spacing-s);
}

.hint {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* 完成頁面樣式 */
.completion {
    text-align: center;
    padding: var(--spacing-l);
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: var(--shadow);
    margin: var(--spacing-m);
}

.completion h1 {
    font-size: clamp(2rem, 6vw, 2.5rem);
    color: var(--success-color);
    margin-bottom: var(--spacing-m);
}

.completion-stats {
    background: rgba(52, 168, 83, 0.1);
    border-radius: 12px;
    padding: var(--spacing-m);
    margin: var(--spacing-m) 0;
}

.completion-stats p {
    font-size: var(--font-size-progress);
    margin: var(--spacing-xs) 0;
    color: var(--text-color);
}

.completion-stats strong {
    color: var(--success-color);
    font-weight: 600;
}

/* 排名成就樣式 */
.rank-achievement {
    border-radius: 12px;
    padding: var(--spacing-m);
    margin: var(--spacing-m) 0;
    font-size: var(--font-size-progress);
    font-weight: 700;
    text-align: center;
}

.rank-1-achievement {
    background: linear-gradient(135deg, #fff3cd 0%, #fff9e6 100%);
    border: 2px solid #ffc107;
    color: #b8860b;
    box-shadow: 0 4px 12px rgba(255, 193, 7, 0.3);
    animation: rank1Celebration 3s ease-in-out;
}

.rank-2-achievement {
    background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
    border: 2px solid #64748b;
    color: #475569;
    box-shadow: 0 4px 12px rgba(100, 116, 139, 0.3);
    animation: rank2Celebration 3s ease-in-out;
}

.rank-3-achievement {
    background: linear-gradient(135deg, #fef3e2 0%, #fed7aa 100%);
    border: 2px solid #f59e0b;
    color: #92400e;
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.3);
    animation: rank3Celebration 3s ease-in-out;
}

.restart-btn {
    font-size: var(--font-size-button);
    padding: var(--spacing-m) var(--spacing-l);
    background: var(--primary-color);
    color: white;
    margin-top: var(--spacing-m);
}

/* === 動畫效果 === */
@keyframes bounce {
    0%, 20%, 60%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    80% { transform: translateY(-5px); }
}

@keyframes rank1Celebration {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 4px 12px rgba(255, 193, 7, 0.3);
    }
    50% {
        transform: scale(1.03);
        box-shadow: 0 6px 16px rgba(255, 193, 7, 0.5);
    }
}

@keyframes rank2Celebration {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 4px 12px rgba(100, 116, 139, 0.3);
    }
    50% {
        transform: scale(1.02);
        box-shadow: 0 6px 14px rgba(100, 116, 139, 0.4);
    }
}

@keyframes rank3Celebration {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 4px 12px rgba(245, 158, 11, 0.3);
    }
    50% {
        transform: scale(1.02);
        box-shadow: 0 6px 14px rgba(245, 158, 11, 0.4);
    }
}

/* === 深色模式支援 === */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #1a1a1a;
        --card-bg: #2d2d2d;
        --text-color: #ffffff;
        --text-secondary: #a0a0a0;
        --border-color: #404040;
    }

    .answer-input,
    .number-btn {
        background: var(--card-bg);
    }

    .leaderboard-item.rank-1,
    .leaderboard-item.rank-2,
    .leaderboard-item.rank-3 {
        background: linear-gradient(135deg, #2a2a2a, #333);
    }
}

/* === 手機橫向模式 (480px+) === */
@media screen and (min-width: 480px) {
    .start-content {
        max-width: 400px;
    }

    .records-content {
        max-width: 500px;
    }

    .question-container {
        padding: var(--spacing-xl);
        min-height: 300px;
    }

    .answer-container {
        max-width: 350px;
    }

    .number-btn {
        width: 70px;
        height: 70px;
        font-size: 1.4rem;
    }
}

/* === 平板模式 (768px+) === */
@media screen and (min-width: 768px) {
    :root {
        --container-max: 1000px;
        --touch-target-large: 80px;
    }

    .app-container {
        padding: var(--spacing-m);
    }

    .start-content {
        max-width: 500px;
        padding: calc(var(--spacing-xl) * 1.5);
    }

    .records-content {
        max-width: 600px;
        padding: var(--spacing-xl);
    }

    .radio-group {
        gap: var(--spacing-m);
    }

    .radio-label {
        flex: 0 1 auto;
        min-width: 100px;
    }

    /* 練習模式在平板上的優化 */
    .practice-type-group {
        flex-direction: row;
        flex-wrap: wrap;
        gap: var(--spacing-m);
    }

    .practice-type-group .radio-label {
        flex: 1 1 250px;
        min-width: 200px;
    }

    .number-checkboxes {
        grid-template-columns: repeat(8, 1fr);
        max-width: 600px;
    }

    .practice-container {
        gap: var(--spacing-m);
    }

    .question-container {
        padding: calc(var(--spacing-xl) * 1.5);
        min-height: 350px;
    }

    .answer-container {
        max-width: 400px;
    }

    .number-btn {
        width: var(--touch-target-large);
        height: var(--touch-target-large);
        font-size: var(--font-size-button);
    }

    /* 平板橫向模式：題目+鍵盤兩欄佈局 */
    @media (orientation: landscape) {
        .practice-container {
            display: grid !important;
            grid-template-columns: 2fr 1fr;
            grid-template-rows: auto auto 1fr;
            gap: var(--spacing-l);
            height: calc(var(--vh, 1vh) * 100);
            padding: var(--spacing-m);
        }

        .header {
            grid-column: 1 / -1;
            grid-row: 1;
        }

        .progress-container {
            grid-column: 1 / -1;
            grid-row: 2;
        }

        .question-container {
            grid-column: 1;
            grid-row: 3;
            display: flex;
            flex-direction: column;
            justify-content: center;
        }

        .number-pad {
            grid-column: 2;
            grid-row: 3;
            display: flex !important;
            flex-direction: column;
            justify-content: center;
            align-self: center;
        }

        .answer-container {
            max-width: 320px;
            margin: 0 auto;
        }
    }
}

/* === 中型平板模式 (900px+) - 優化 iPad Mini === */
@media screen and (min-width: 900px) {
    :root {
        --container-max: 1200px;
        --font-size-question: 1.8rem;
        --touch-target-large: 70px;
    }

    .app-container {
        max-width: var(--container-max);
        padding: var(--spacing-l);
    }

    .start-content {
        max-width: 550px;
        padding: calc(var(--spacing-xl) * 1.2);
    }

    .question-container {
        padding: calc(var(--spacing-xl) * 1.2);
        min-height: 300px;
    }

    .answer-container {
        max-width: 350px;
    }

    .number-btn {
        width: var(--touch-target-large);
        height: var(--touch-target-large);
    }
}

/* === 桌面模式 (1024px+ 滑鼠操作) === */
@media screen and (min-width: 1024px) and (pointer: fine) {
    :root {
        /* 桌面字體調整 */
        --font-size-title: 1.8rem;
        --font-size-question: 2rem;
        --font-size-input: 1.5rem;
        --font-size-button: 1.2rem;
        --font-size-progress: 1rem;
        --touch-target-large: 50px;
        --container-max: 1400px;
    }

    .app-container {
        max-width: var(--container-max);
        padding: var(--spacing-l) var(--spacing-xl);
    }

    .start-content {
        max-width: 600px;
    }

    .records-content {
        max-width: 700px;
    }

    /* 桌面練習佈局 */
    .practice-container {
        display: grid;
        grid-template-columns: 1fr;
        grid-template-rows: auto auto 1fr;
        gap: var(--spacing-l);
        height: calc(var(--vh, 1vh) * 100);
        max-width: none;
        padding: var(--spacing-l) var(--spacing-xl);
        margin: 0 auto;
    }

    .header {
        grid-column: 1;
        grid-row: 1;
    }

    .progress-container {
        grid-column: 1;
        grid-row: 2;
    }

    .question-container {
        grid-column: 1;
        grid-row: 3;
        display: flex;
        flex-direction: column;
        justify-content: center;
        min-height: 400px;
    }

    /* 桌面版隱藏虛擬鍵盤 */
    .number-pad {
        display: none !important;
    }

    /* 桌面版的提示已經整合到 question-container 內 */

    /* 桌面版提示 */
    .hint::before {
        content: "💻 ";
    }

    .hint::after {
        content: "使用鍵盤輸入答案，輸入完成後自動檢查";
        display: block;
        margin-top: var(--spacing-xs);
        font-size: 0.8rem;
        opacity: 0.8;
    }

    /* 桌面版答案輸入區優化 */
    .answer-container {
        max-width: 350px;
        margin: 0 auto;
    }

    .answer-input {
        cursor: text;
        max-width: 200px;
        font-size: 1.5rem;
        padding: 0.75rem;
    }

    .answer-input:hover {
        border-color: var(--primary-color);
    }

    .submit-btn {
        padding: 0.75rem 1.5rem;
        min-width: 100px;
        height: auto;
        font-size: 1.2rem;
    }

    .submit-btn:hover {
        box-shadow: 0 4px 12px rgba(66, 133, 244, 0.3);
    }

    .completion {
        max-width: 600px;
        margin: var(--spacing-xl) auto;
    }
}

/* === 大螢幕桌面 (1440px+) === */
@media screen and (min-width: 1440px) {
    :root {
        --font-size-question: 2.2rem;
        --font-size-input: 1.6rem;
        --container-max: 1400px;
    }

    .practice-container {
        max-height: 900px;
    }

    .question-container {
        min-height: 450px;
    }
}

/* === 超寬螢幕 (1920px+) === */
@media screen and (min-width: 1920px) {
    .app-container {
        max-width: 1400px;
    }

    .question-container {
        padding: calc(var(--spacing-xl) * 2);
    }
}

/* === 觸控裝置強制顯示虛擬鍵盤 === */
@media screen and (pointer: coarse) {
    .number-pad {
        display: flex !important;
        flex-direction: column;
        justify-content: center;
    }
}

/* === iPad Pro 等大螢幕觸控裝置 (1024px+ 觸控) === */
@media screen and (min-width: 1024px) and (pointer: coarse) {
    :root {
        /* 大螢幕觸控裝置字體 */
        --font-size-question: 2.2rem;
        --font-size-input: 2rem;
        --touch-target-large: 90px;
    }

    /* iPad Pro 橫向模式優化 */
    @media (orientation: landscape) {
        .practice-container {
            display: grid !important;
            grid-template-columns: 2fr 1fr !important;
            grid-template-rows: auto auto 1fr !important;
            gap: var(--spacing-l) !important;
            height: calc(var(--vh, 1vh) * 100) !important;
            padding: var(--spacing-m) !important;
        }

        .header {
            grid-column: 1 / -1;
            grid-row: 1;
        }

        .progress-container {
            grid-column: 1 / -1;
            grid-row: 2;
        }

        .question-container {
            grid-column: 1;
            grid-row: 3;
            display: flex;
            flex-direction: column;
            justify-content: center;
            min-height: auto;
        }

        .number-pad {
            grid-column: 2;
            grid-row: 3;
            display: flex !important;
            flex-direction: column;
            justify-content: center;
        }
    }
}

/* === 語音錯誤記錄樣式 === */
.error-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-m);
    margin: var(--spacing-s) 0;
    background: var(--card-bg);
    border-left: 4px solid var(--error-color);
    border-radius: 0 8px 8px 0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    transition: all 0.2s ease;
}

.error-item:hover {
    background: #f0f2f5;
    transform: translateX(2px);
}

.error-content {
    flex: 1;
}

.error-main {
    margin-bottom: var(--spacing-xs);
    font-size: 1rem;
}

.error-text {
    color: var(--error-color);
    font-weight: 500;
}

.error-meta {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.3;
}

.delete-btn {
    background: none;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    opacity: 0.6;
    padding: var(--spacing-xs);
    border-radius: 4px;
    transition: all 0.2s ease;
    min-width: var(--touch-target);
    min-height: var(--touch-target);
    display: flex;
    align-items: center;
    justify-content: center;
}

.delete-btn:hover {
    opacity: 1;
    background: rgba(234, 67, 53, 0.1);
    transform: scale(1.1);
}

/* 按鈕群組樣式 */
.button-group {
    display: flex;
    gap: var(--spacing-m);
    justify-content: center;
    flex-wrap: wrap;
    margin-top: var(--spacing-l);
}

/* 響應式優化 - 語音錯誤記錄 */
@media screen and (max-width: 480px) {
    .error-item {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-s);
        padding: var(--spacing-s);
    }

    .delete-btn {
        align-self: flex-end;
        margin-top: var(--spacing-xs);
    }

    .error-meta {
        font-size: 0.8rem;
    }

    .button-group {
        flex-direction: column;
        gap: var(--spacing-s);
    }

    .button-group button {
        width: 100%;
    }
}