/* 全局样式 */
:root {
    --primary-color: #4A90D9;
    --primary-dark: #3A7BC8;
    --success-color: #52C41A;
    --error-color: #FF4D4F;
    --warning-color: #FAAD14;
    --text-primary: #333;
    --text-secondary: #666;
    --bg-color: #F5F7FA;
    --card-bg: #fff;
    --border-color: #E8E8E8;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --radius: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.app-container {
    max-width: 480px;
    margin: 0 auto;
    min-height: 100vh;
    background: var(--card-bg);
    display: flex;
    flex-direction: column;
}

/* 顶部导航 */
.header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 20px;
    text-align: center;
}

.header h1 {
    font-size: 20px;
    margin-bottom: 10px;
}

.header-stats {
    display: flex;
    justify-content: center;
    gap: 20px;
    font-size: 14px;
}

.header-stats strong {
    color: #FFD700;
}

/* 主导航 */
.main-nav {
    display: flex;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-btn {
    flex: 1;
    padding: 12px;
    border: none;
    background: none;
    font-size: 14px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s;
    border-bottom: 2px solid transparent;
}

.nav-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
    font-weight: 600;
}

/* 页面内容 */
.content {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
}

.page {
    display: none;
}

.page.active {
    display: block;
}

/* 单词卡片 */
.word-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 30px 20px;
    text-align: center;
    margin-bottom: 20px;
}

.word-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.word-book {
    background: var(--primary-color);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
}

.word-difficulty {
    font-size: 14px;
}

.word-content {
    margin-bottom: 20px;
}

.word-text {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.word-phonetic {
    color: var(--text-secondary);
    font-size: 16px;
    margin-bottom: 12px;
}

.play-audio-btn {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s;
}

.play-audio-btn:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.word-meaning {
    background: #F0F7FF;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 15px;
}

.word-meaning p {
    font-size: 18px;
    color: var(--primary-color);
    font-weight: 500;
}

.word-example {
    background: #FFF9E6;
    padding: 15px;
    border-radius: 8px;
    text-align: left;
}

.word-example h4 {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.example-en {
    font-size: 14px;
    color: var(--text-primary);
    margin-bottom: 5px;
    font-style: italic;
}

.example-cn {
    font-size: 13px;
    color: var(--text-secondary);
}

/* 年级和单元标签 */
.word-info {
    display: flex;
    justify-content: center;
    gap: 6px;
    padding: 6px 0;
}

.grade-tag, .module-tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 500;
}

.grade-tag {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
}

.grade-tag::before {
    content: "📖";
    font-size: 10px;
}

.module-tag {
    background: linear-gradient(135deg, #f093fb, #f5576c);
    color: white;
}

.module-tag::before {
    content: "📚";
    font-size: 10px;
}

/* 导航按钮 */
.nav-buttons {
    display: flex;
    justify-content: space-between;
    gap: 10px;
    margin-top: 20px;
    padding: 0 10px;
}

.nav-buttons .btn {
    flex: 1;
    padding: 12px 8px;
    font-size: 14px;
}

.btn-secondary {
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

.btn-secondary:hover {
    background: var(--primary-dark);
}

.btn-outline {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
}

.btn-outline:hover {
    background: var(--bg-color);
}

/* 三维筛选范围 */
.range-select {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: 12px;
    background: #f5f5f5;
    border-radius: 8px;
    margin-bottom: 15px;
}

.range-row {
    display: flex;
    align-items: center;
    gap: 10px;
}

.range-row .range-label {
    font-size: 14px;
    color: var(--text-secondary);
    min-width: 40px;
}

.range-row .range-select,
.range-row select {
    flex: 1;
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 14px;
    background: white;
    color: var(--text-primary);
}

.range-row select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.range-info {
    text-align: center;
    padding: 10px;
    background: #e8f5e9;
    border-radius: 8px;
    margin-bottom: 10px;
    font-size: 14px;
    color: #2e7d32;
}

/* 按钮样式 */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 500;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-large {
    width: 100%;
    padding: 16px;
    font-size: 18px;
    margin-bottom: 15px;
}

.action-buttons {
    margin-bottom: 20px;
}

.mode-select {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.mode-btn {
    flex: 1;
    padding: 10px;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s;
}

.mode-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* 答题选项 */
.quiz-options {
    margin-top: 20px;
}

.quiz-question {
    text-align: center;
    font-size: 16px;
    margin-bottom: 15px;
    color: var(--text-secondary);
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.option-btn {
    padding: 15px;
    border: 2px solid var(--border-color);
    background: var(--card-bg);
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.option-btn:hover {
    border-color: var(--primary-color);
    background: #F0F7FF;
}

.option-btn.correct {
    border-color: var(--success-color);
    background: #F6FFED;
}

.option-btn.wrong {
    border-color: var(--error-color);
    background: #FFF2F0;
}

/* 拼写模式 */
.spelling-mode {
    text-align: center;
}

.spelling-hint {
    font-size: 24px;
    font-weight: 600;
    color: var(--primary-color);
    margin: 20px 0;
}

.spelling-input {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 18px;
    text-align: center;
    margin-bottom: 15px;
}

.spelling-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* 复习页面 */
.review-info {
    text-align: center;
    padding: 30px 0;
}

.review-info h2 {
    margin-bottom: 10px;
}

.review-info p {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.review-stats {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 30px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 36px;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    font-size: 14px;
    color: var(--text-secondary);
}

/* 词库页面 */
.words-filter {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 20px;
}

.filter-select {
    flex: 1;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    background: white;
}

.words-list {
    max-height: 400px;
    overflow-y: auto;
}

.word-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px;
    border-bottom: 1px solid var(--border-color);
}

.word-item-info h4 {
    font-size: 16px;
    margin-bottom: 4px;
}

.word-item-info p {
    font-size: 13px;
    color: var(--text-secondary);
}

.word-item-status {
    font-size: 12px;
    padding: 4px 8px;
    border-radius: 4px;
}

.word-item-status.new {
    background: #E6F7FF;
    color: var(--primary-color);
}

.word-item-status.learning {
    background: #FFFBE6;
    color: var(--warning-color);
}

.word-item-status.mastered {
    background: #F6FFED;
    color: var(--success-color);
}

.empty-tip {
    text-align: center;
    color: var(--text-secondary);
    padding: 40px;
}

/* 统计页面 */
.stats-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.stats-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    text-align: center;
}

.stats-card h3 {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.progress-bar {
    height: 8px;
    background: var(--bg-color);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 8px;
}

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

.progress-text {
    font-size: 13px;
    color: var(--text-secondary);
}

.stat-large {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary-color);
}

/* 手写输入样式 */
.input-mode-toggle {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 15px;
}

.mode-toggle-btn {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    background: white;
    border-radius: 20px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.mode-toggle-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.keyboard-input-area {
    display: flex;
    gap: 10px;
    justify-content: center;
    align-items: center;
}

.handwriting-area {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

#handwriting-canvas {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    background: white;
    cursor: crosshair;
    touch-action: none;
}

.handwriting-controls {
    display: flex;
    gap: 10px;
}

/* 手写识别状态提示（替代弹窗） */
.recognized-status {
    font-size: 18px;
    font-weight: 600;
    min-height: 36px;
    text-align: center;
    padding: 6px 12px;
    border-radius: 8px;
    transition: all 0.3s;
    width: 100%;
}

.recognized-status.correct {
    color: var(--success-color);
    background: #F6FFED;
}

.recognized-status.wrong {
    color: var(--error-color);
    background: #FFF2F0;
}

.recognized-status.pending {
    color: var(--primary-color);
    background: #E6F7FF;
}

.recognized-status.error {
    color: var(--error-color);
    background: #FFF2F0;
}

/* 本次练习统计 */
.session-stats {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 15px;
    padding: 10px;
    background: var(--bg-color);
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
}

.session-stats .stat-correct {
    color: var(--success-color);
}

.session-stats .stat-wrong {
    color: var(--error-color);
}

/* 例句展示区 */
.example-reveal {
    margin: 10px 0;
    text-align: center;
}

.example-reveal-inner {
    background: #FFF9E6;
    padding: 15px;
    border-radius: 8px;
    text-align: left;
    border-left: 4px solid #FAAD14;
}

.example-reveal-en {
    font-size: 16px;
    color: var(--text-primary);
    margin-bottom: 6px;
    font-style: italic;
}

.example-reveal-cn {
    font-size: 14px;
    color: var(--text-secondary);
}

/* 例句按钮 */
.example-btn-area {
    display: flex;
    justify-content: center;
    margin: 10px 0;
}

.btn-example {
    background: #FFF9E6;
    color: #D48806;
    border: 1px solid #FFE58F;
    border-radius: 20px;
    padding: 8px 20px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-example:hover {
    background: #FFF3BF;
}

.btn-example:active {
    background: #FFE58F;
}

/* ==================== 打印页面样式 ==================== */
.print-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.print-options {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 15px;
}

.print-options h3 {
    margin: 0 0 15px 0;
    font-size: 16px;
    color: var(--text-primary);
}

.option-group {
    margin-bottom: 12px;
}

.option-group > label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text-secondary);
    font-size: 13px;
}

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

.template-btn {
    padding: 8px 4px;
    border: 2px solid var(--border-color);
    background: var(--bg-color);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 13px;
    text-align: center;
}

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

.template-btn.active {
    border-color: var(--primary-color);
    background: #E6F7FF;
}

.template-icon {
    font-size: 24px;
    margin-bottom: 4px;
    display: block;
}

.grade-checkboxes {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.grade-checkboxes label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    cursor: pointer;
}

.grade-checkboxes input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.print-input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    background: var(--bg-color);
    color: var(--text-primary);
}

.print-select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    background: var(--bg-color);
    color: var(--text-primary);
}

.print-actions {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

.print-actions .btn {
    flex: 1;
}

/* 打印预览区 */
.print-preview {
    background: var(--bg-color);
    border-radius: 12px;
    padding: 20px;
    overflow-y: auto;
}

.preview-tip {
    text-align: center;
    color: var(--text-secondary);
    padding: 40px 0;
    font-size: 14px;
}

/* 打印纸样式 */
.print-paper {
    font-family: "SimSun", "宋体", serif;
    line-height: 2;
}

.print-paper-header {
    text-align: center;
    border-bottom: 2px solid #333;
    padding-bottom: 10px;
    margin-bottom: 20px;
}

.print-paper-title {
    font-size: 24px;
    font-weight: bold;
    margin: 0;
}

.print-paper-info {
    display: flex;
    justify-content: space-between;
    margin-top: 10px;
    font-size: 14px;
}

.print-word-item {
    display: flex;
    align-items: flex-start;
    padding: 8px 0;
    border-bottom: 1px dashed #ddd;
    page-break-inside: avoid;
}

.print-word-number {
    width: 30px;
    font-weight: bold;
    color: #666;
}

.print-word-content {
    flex: 1;
}

/* 汉译英样式 */
.print-cn-en .english-line {
    border-bottom: 1px solid #333;
    min-height: 24px;
    margin-top: 20px;
}

/* 英译汉样式 */
.print-en-cn .chinese-line {
    border-bottom: 1px solid #333;
    min-height: 24px;
    margin-top: 20px;
}

/* 默写样式 */
.print-dictation .word-line {
    display: flex;
    align-items: baseline;
    gap: 10px;
    margin: 15px 0;
}

.print-dictation .phonetic {
    font-size: 14px;
    color: #666;
}

.print-dictation .meaning {
    font-size: 14px;
    color: #333;
}

/* 填空题样式 */
.print-fill-blank .blank-line {
    margin: 15px 0;
}

.print-fill-blank .english-sentence {
    font-size: 16px;
}

.print-fill-blank .blank-underline {
    display: inline-block;
    min-width: 80px;
    border-bottom: 1px solid #333;
}

/* 单词表样式 */
.print-word-list .list-item {
    display: inline-block;
    width: 30%;
    padding: 5px 10px;
    margin: 5px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}

/* 打印媒体查询 */
@media print {
    body * {
        visibility: hidden;
    }
    
    .print-paper, .print-paper * {
        visibility: visible;
    }
    
    .print-paper {
        position: absolute;
        left: 0;
        top: 0;
        width: 100%;
        margin: 0;
        padding: 15mm;
        box-shadow: none;
    }
}