/* ========================================
   共读图书阅读器样式 - 单词级别高亮版
   参考 mirra.css 风格
   ======================================== */

:root {
    /* 主文字带状背景参数 */
    --band-top: 0.85em;
    --band-height: 1.4em;
    --band-xpad: 2px;
    --band-radius: 6px;
    --word-margin-x: 4px;
    --highlight-offset-y: -4px;

    /* 下划线参数 */
    --underline-thickness: 6px;
    --underline-offset: 1px;
    --underline-offset-adjust: -2px;

    /* 墨水屏主题 */
    --ink-bg: #FAF9F6;
    --ink-paper: #F4F1EA;
    --ink-text: #2C2C2C;
    --ink-text-light: #5A5A5A;
    --ink-muted: #8B8B8B;
    --ink-highlight: #FFF9E6;
    --ink-highlight-border: #D4A574;
    --ink-accent: #8B7355;
    --ink-border: #E0DCD4;

    /* 明亮主题 */
    --light-bg: #FFFFFF;
    --light-paper: #FFFFFF;
    --light-text: #333333;
    --light-text-light: #555555;
    --light-muted: #888888;
    --light-highlight: #E3F2FD;
    --light-highlight-border: #2196F3;
    --light-accent: #2196F3;
    --light-border: #E0E0E0;

    /* 夜间主题 */
    --dark-bg: #1A1A1A;
    --dark-paper: #242424;
    --dark-text: #E0E0E0;
    --dark-text-light: #B0B0B0;
    --dark-muted: #888888;
    --dark-highlight: #2D3748;
    --dark-highlight-border: #4A5568;
    --dark-accent: #63B3ED;
    --dark-border: #333333;

    /* 当前使用的变量（默认墨水屏） */
    --bg-color: var(--ink-bg);
    --paper-color: var(--ink-paper);
    --text-color: var(--ink-text);
    --text-light: var(--ink-text-light);
    --muted-color: var(--ink-muted);
    --highlight-color: var(--ink-highlight);
    --highlight-border: var(--ink-highlight-border);
    --accent-color: var(--ink-accent);
    --border-color: var(--ink-border);
}

/* 主题切换 */
.reader-container.theme-ink {
    --bg-color: var(--ink-bg);
    --paper-color: var(--ink-paper);
    --text-color: var(--ink-text);
    --text-light: var(--ink-text-light);
    --muted-color: var(--ink-muted);
    --highlight-color: var(--ink-highlight);
    --highlight-border: var(--ink-highlight-border);
    --accent-color: var(--ink-accent);
    --border-color: var(--ink-border);
}

.reader-container.theme-light {
    --bg-color: var(--light-bg);
    --paper-color: var(--light-paper);
    --text-color: var(--light-text);
    --text-light: var(--light-text-light);
    --muted-color: var(--light-muted);
    --highlight-color: var(--light-highlight);
    --highlight-border: var(--light-highlight-border);
    --accent-color: var(--light-accent);
    --border-color: var(--light-border);
}

.reader-container.theme-dark {
    --bg-color: var(--dark-bg);
    --paper-color: var(--dark-paper);
    --text-color: var(--dark-text);
    --text-light: var(--dark-text-light);
    --muted-color: var(--dark-muted);
    --highlight-color: var(--dark-highlight);
    --highlight-border: var(--dark-highlight-border);
    --accent-color: var(--dark-accent);
    --border-color: var(--dark-border);
}

/* 基础布局 */
.reader-container {
    min-height: 100vh;
    background: var(--bg-color);
    color: var(--text-color);
    font-family: 'Noto Serif JP', 'Source Han Serif', 'Hiragino Mincho Pro', serif;
    display: flex;
    flex-direction: column;
}

/* 顶部导航 */
.reader-header {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    background: var(--paper-color);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.back-btn {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 14px;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

.back-btn:hover {
    text-decoration: underline;
}

.reader-header .book-info {
    text-align: center;
    flex: 1;
    padding: 0 16px;
}

.reader-header .book-title {
    font-weight: 500;
    font-size: 14px;
}

.reader-header .chapter-title {
    font-size: 12px;
    color: var(--muted-color);
    margin-left: 8px;
}

.header-actions {
    display: flex;
    gap: 8px;
}

.icon-btn {
    background: none;
    border: none;
    font-size: 18px;
    cursor: pointer;
    padding: 8px;
    opacity: 0.7;
    transition: opacity 0.2s;
    color: var(--text-color);
    border-radius: 8px;
}

.icon-btn:hover {
    opacity: 1;
    background: var(--border-color);
}

/* 内容区域 */
.content-area {
    flex: 1;
    overflow-y: auto;
    padding: 30px 20px;
    padding-bottom: 160px; /* 为固定底部播放器留出空间 */
}

.sentences-wrapper {
    max-width: 800px;
    margin: 0 auto;
}

/* ========================================
   句子卡片样式
   ======================================== */
.sentence-block {
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px 20px;
    margin-bottom: 12px;
    transition: all 0.3s ease;
    cursor: pointer;
    background: var(--paper-color);
}

.sentence-block:hover {
    border-color: var(--accent-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

/* 当前播放句子高亮 */
.sentence-block.active {
    background: var(--highlight-color);
    border-color: var(--highlight-border);
    box-shadow: 0 4px 16px rgba(139, 115, 85, 0.15);
}

/* ========================================
   单词样式 - 核心高亮系统
   ======================================== */
.word {
    display: inline-block;
    margin: 4px var(--word-margin-x);
    padding: 4px 8px;
    border-radius: 8px;
    font-weight: 500;
    line-height: 1.6;
    background-color: transparent;
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
}

.word:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
}

.word-text {
    position: relative;
    z-index: 1;
    text-decoration: none;
    --underline-color: currentColor;
}

/* 当前播放句子中的单词下划线 */
.sentence-block.active .word-text {
    position: relative;
    text-decoration: none !important;
    z-index: 0;
}

.sentence-block.active .word-text::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    height: var(--underline-thickness);
    background: var(--underline-color, currentColor);
    bottom: calc(var(--underline-offset) * -1);
    transform: translateY(var(--underline-offset-adjust));
    border-radius: 2px;
    pointer-events: none;
    z-index: -1;
}

/* 当前跟读单词高亮（绿色聚光效果） */
.word.highlight {
    position: relative;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.word.highlight::before {
    content: "";
    position: absolute;
    left: calc((var(--band-xpad) + var(--word-margin-x)) * -1);
    right: calc((var(--band-xpad) + var(--word-margin-x)) * -1);
    top: var(--band-top);
    height: var(--band-height);
    border-radius: var(--band-radius);
    background-color: rgba(21, 128, 61, 0.08);
    box-shadow: inset 0 0 0 3px #15803d, 0 0 6px rgba(21, 128, 61, 0.4);
    z-index: 0;
    pointer-events: none;
    transform: translateY(var(--highlight-offset-y));
}

.word.highlight > * {
    position: relative;
    z-index: 1;
}

/* ========================================
   词性颜色系统 - 下划线颜色
   ======================================== */
.pos-noun .word-text { --underline-color: #fff46c; }
.pos-verb .word-text { --underline-color: #b8df86; }
.pos-adjective .word-text { --underline-color: #f1c9e1; }
.pos-adverb .word-text { --underline-color: #a88bf3; }
.pos-particle .word-text { --underline-color: #93d8db; }
.pos-aux .word-text { --underline-color: #aaaaaa; }
.pos-conj .word-text { --underline-color: transparent; }
.pos-intj .word-text { --underline-color: #93d8db; }
.pos-prefix .word-text { --underline-color: #f59e0b; }
.pos-suffix .word-text { --underline-color: transparent; }
.pos-symbol .word-text { --underline-color: #6b7280; }
.pos-other .word-text { --underline-color: transparent; }

/* ========================================
   注音样式 (Ruby)
   ======================================== */
.japanese-text {
    font-size: 22px;
    line-height: 2.2;
    letter-spacing: 0.03em;
    margin-bottom: 12px;
}

ruby {
    ruby-align: center;
}

ruby rt {
    font-size: 10px;
    color: var(--muted-color);
    font-family: 'Noto Sans JP', sans-serif;
    font-weight: 400;
}

/* ========================================
   翻译文本
   ======================================== */
.translation-text {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.8;
    padding-left: 16px;
    border-left: 3px solid var(--border-color);
    font-family: 'Noto Sans SC', 'PingFang SC', sans-serif;
    margin-top: 8px;
}

.translation-text.hidden {
    display: none;
}

/* 空内容提示 */
.empty-sentences {
    text-align: center;
    padding: 60px 20px;
    color: var(--muted-color);
}

/* ========================================
   底部固定播放器 - 现代风格
   ======================================== */
.audio-player-wrapper {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--paper-color);
    border-top: 1px solid var(--border-color);
    padding: 12px 20px;
    padding-bottom: calc(12px + env(safe-area-inset-bottom, 0px));
    box-shadow: 0 -4px 24px rgba(0, 0, 0, 0.12);
}

/* 章节导航行 */
.player-nav-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 10px;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

.chapter-nav {
    min-width: 70px;
}

.nav-btn {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    transition: opacity 0.2s;
}

.nav-btn:hover {
    opacity: 0.8;
}

/* 进度条区域 */
.progress-wrapper {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 14px;
    font-size: 12px;
    color: var(--muted-color);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-variant-numeric: tabular-nums;
}

.progress-slider {
    flex: 1;
    -webkit-appearance: none;
    height: 4px;
    background: var(--border-color);
    border-radius: 2px;
    cursor: pointer;
    transition: height 0.2s;
}

.progress-slider:hover {
    height: 6px;
}

.progress-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    background: var(--accent-color);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    transition: transform 0.2s;
}

.progress-slider:hover::-webkit-slider-thumb {
    transform: scale(1.2);
}

.progress-slider::-moz-range-thumb {
    width: 14px;
    height: 14px;
    background: var(--accent-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

/* 播放器主体 - 现代居中布局 */
.audio-player {
    max-width: 400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
}

/* 现代圆形播放按钮 */
.play-btn {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    border: none;
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: white;
    font-size: 18px;
    cursor: pointer;
    transition: all 0.2s ease;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 8px 24px rgba(245, 158, 11, 0.35);
}

.play-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 12px 32px rgba(245, 158, 11, 0.45);
}

.play-btn:active {
    transform: scale(0.98);
}

.play-btn.playing {
    background: linear-gradient(135deg, #15803d 0%, #166534 100%);
    box-shadow: 0 8px 24px rgba(21, 128, 61, 0.35);
}

.play-btn svg {
    width: 22px;
    height: 22px;
}

/* 播放器控制按钮组 */
.player-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

/* 现代圆形控制按钮 */
.control-btn {
    appearance: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: var(--paper-color);
    color: var(--text-light);
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.control-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.12);
}

.control-btn:active {
    transform: scale(0.95);
}

.control-btn.active {
    background: #fef3c7;
    border-color: #f59e0b;
    color: #b45309;
    box-shadow: 0 6px 16px rgba(245, 158, 11, 0.2);
}

.control-btn svg {
    width: 18px;
    height: 18px;
}

.control-btn:focus,
.control-btn:focus-visible {
    outline: none;
}

/* 速度选择器 - 现代风格 */
.speed-select {
    appearance: none;
    width: 52px;
    height: 40px;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 0 8px;
    font-size: 12px;
    font-weight: 600;
    text-align: center;
    background: var(--paper-color);
    color: var(--text-light);
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

.speed-select:hover {
    border-color: var(--accent-color);
}

.speed-select:focus {
    outline: none;
    border-color: var(--accent-color);
}

/* ========================================
   单词弹窗
   ======================================== */
.word-popup {
    position: fixed;
    bottom: 180px;
    left: 50%;
    transform: translateX(-50%);
    width: 90%;
    max-width: 380px;
    background: var(--paper-color);
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    z-index: 200;
    overflow: hidden;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

.word-popup.hidden {
    display: none;
}

.popup-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
    background: linear-gradient(to bottom, var(--paper-color), rgba(0,0,0,0.02));
}

.popup-word {
    font-size: 28px;
    font-weight: 600;
    font-family: 'Noto Serif JP', serif;
    color: var(--text-color);
}

.popup-reading {
    font-size: 14px;
    color: var(--muted-color);
    font-style: italic;
}

.btn-add-vocab {
    margin-left: auto;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 20px;
    padding: 8px 16px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-add-vocab:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.btn-add-vocab:disabled {
    background: var(--muted-color);
    cursor: not-allowed;
}

.popup-body {
    padding: 20px;
}

.popup-pos {
    display: inline-block;
    font-size: 12px;
    font-weight: 600;
    color: white;
    background: var(--accent-color);
    padding: 4px 12px;
    border-radius: 12px;
    margin-bottom: 12px;
}

/* 词性标签颜色 */
.popup-pos.pos-noun { background: #3b82f6; }
.popup-pos.pos-verb { background: #ef4444; }
.popup-pos.pos-adjective { background: #eab308; }
.popup-pos.pos-adverb { background: #8b5cf6; }
.popup-pos.pos-particle { background: #22c55e; }
.popup-pos.pos-aux { background: #06b6d4; }

.popup-meaning {
    font-size: 18px;
    line-height: 1.6;
    color: var(--text-color);
}

/* AI 查词样式 */
.popup-ai-loading {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 0;
    color: var(--muted-color);
    font-size: 14px;
}

.popup-ai-loading.hidden {
    display: none;
}

.loading-spinner-small {
    width: 16px;
    height: 16px;
    border: 2px solid var(--border-color);
    border-top-color: var(--accent-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.popup-ai-result {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px dashed var(--border-color);
}

.popup-ai-result.hidden {
    display: none;
}

.popup-definitions {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-color);
}

.popup-definitions .def-item {
    margin-bottom: 4px;
}

/* 核心释义样式 */
.popup-definitions .def-core {
    font-weight: 500;
    color: var(--text-color);
}

/* 其他含义样式 */
.popup-definitions .def-extra {
    color: var(--muted-color);
    font-size: 13px;
    padding-left: 8px;
    border-left: 2px solid var(--border-color);
    margin-left: 4px;
}

/* 搭配词组 */
.collocation-section {
    margin-top: 8px;
    font-size: 13px;
    color: var(--text-light);
}

.collocation-section strong {
    color: var(--accent-color);
}

/* 记忆技巧 */
.memory-tip {
    margin-top: 8px;
    font-size: 13px;
    color: var(--accent-color);
    background: rgba(var(--accent-rgb, 99, 179, 237), 0.1);
    padding: 6px 10px;
    border-radius: 4px;
}

/* 使用说明 */
.usage-note {
    margin-top: 6px;
    font-size: 12px;
    font-style: italic;
    color: var(--muted-color);
}

.popup-example {
    margin-top: 12px;
    padding: 10px 12px;
    background: rgba(0, 0, 0, 0.03);
    border-radius: 6px;
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-color);
}

.popup-example.hidden {
    display: none;
}

.popup-example-cn {
    margin-top: 6px;
    font-size: 14px;
    color: var(--muted-color);
    font-style: italic;
}

.popup-example-cn.hidden {
    display: none;
}

.popup-footer {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    padding: 16px 20px;
    border-top: 1px solid var(--border-color);
    background: rgba(0, 0, 0, 0.02);
}

.btn-close-popup {
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    background: var(--border-color);
    border: none;
    color: var(--text-color);
    transition: all 0.2s;
}

.btn-close-popup:hover {
    background: var(--muted-color);
    color: white;
}

/* ========================================
   侧边栏（目录/设置）
   ======================================== */
.toc-sidebar,
.settings-panel {
    position: fixed;
    top: 0;
    right: 0;
    width: 320px;
    height: 100vh;
    background: var(--paper-color);
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.1);
    z-index: 300;
    overflow-y: auto;
    transform: translateX(100%);
    transition: transform 0.3s ease;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

.toc-sidebar.visible,
.settings-panel.visible {
    transform: translateX(0);
}

.toc-sidebar.hidden,
.settings-panel.hidden {
    transform: translateX(100%);
}

.toc-header,
.settings-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.toc-header h3,
.settings-header h3 {
    margin: 0;
    font-size: 16px;
    font-weight: 500;
}

.btn-close-sidebar {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--muted-color);
    padding: 0;
    line-height: 1;
}

.btn-close-sidebar:hover {
    color: var(--text-color);
}

.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.toc-item a {
    display: block;
    padding: 16px 20px;
    color: var(--text-color);
    text-decoration: none;
    border-bottom: 1px solid var(--border-color);
    transition: background 0.2s;
}

.toc-item a:hover,
.toc-item.active a {
    background: var(--highlight-color);
}

.toc-item.active a {
    color: var(--accent-color);
    font-weight: 500;
}

/* 设置面板 */
.settings-body {
    padding: 20px;
}

.setting-item {
    margin-bottom: 24px;
}

.setting-item label {
    display: block;
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 12px;
}

.setting-control {
    display: flex;
    align-items: center;
    gap: 12px;
}

.setting-control input[type="range"] {
    flex: 1;
    -webkit-appearance: none;
    height: 4px;
    background: var(--border-color);
    border-radius: 2px;
}

.setting-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    background: var(--accent-color);
    border-radius: 50%;
    cursor: pointer;
}

.setting-control span {
    min-width: 40px;
    text-align: right;
    font-size: 13px;
    color: var(--muted-color);
}

.theme-options {
    display: flex;
    gap: 8px;
}

.theme-btn {
    flex: 1;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: transparent;
    cursor: pointer;
    font-size: 13px;
    color: var(--text-color);
    transition: all 0.2s;
}

.theme-btn:hover {
    border-color: var(--accent-color);
}

.theme-btn.active {
    border-color: var(--accent-color);
    color: var(--accent-color);
    background: rgba(139, 115, 85, 0.1);
}

/* 遮罩层 */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 250;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
    backdrop-filter: blur(2px);
}

.sidebar-overlay.visible {
    opacity: 1;
    visibility: visible;
}

.sidebar-overlay.hidden {
    opacity: 0;
    visibility: hidden;
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 768px) {
    :root {
        --word-margin-x: 4px;
        --band-top: 0.95em;
        --highlight-offset-y: -1px;
        --underline-thickness: 4px;
    }

    /* 与 mirra.css 保持一致的 ruby 样式 */
    ruby {
        font-size: 1em !important;
    }

    ruby rt {
        font-size: 0.65em !important;
        line-height: 1;
        transform: translateY(-0.1em);
    }

    /* 移动端播放器 - 重新布局 */
    .audio-player-wrapper {
        padding: 10px 16px;
        padding-bottom: calc(10px + env(safe-area-inset-bottom, 0px));
    }

    .player-nav-row {
        margin-bottom: 8px;
    }

    /* 移动端播放器主体：换行布局 */
    .audio-player {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 10px;
        flex-wrap: wrap;
        max-width: 100%;
    }

    /* 移动端进度条占满一行 */
    .progress-wrapper {
        width: 100%;
        order: 1;
        margin-bottom: 8px;
        gap: 8px;
    }

    .progress-slider {
        height: 3px;
    }

    .progress-slider::-webkit-slider-thumb {
        width: 12px;
        height: 12px;
    }

    /* 播放按钮居中 */
    .play-btn {
        width: 48px;
        height: 48px;
        flex-shrink: 0;
        order: 2;
    }

    .play-btn svg {
        width: 20px;
        height: 20px;
    }

    /* 控制按钮在播放按钮右侧 */
    .player-controls {
        display: flex;
        align-items: center;
        gap: 6px;
        order: 3;
    }

    .control-btn {
        width: 34px;
        height: 34px;
    }

    .control-btn svg {
        width: 15px;
        height: 15px;
    }

    .speed-select {
        width: 44px;
        height: 34px;
        font-size: 11px;
    }

    .content-area {
        padding: 20px 12px;
        padding-bottom: 180px;
    }

    .japanese-text {
        font-size: 18px;
        line-height: 2;
    }

    .word {
        margin: 3px 3px;
        padding: 3px 6px;
        font-size: 16px;
        border-radius: 6px;
    }

    .sentence-block {
        padding: 14px 16px;
        border-radius: 10px;
    }

    .toc-sidebar,
    .settings-panel {
        width: 100%;
    }

    .reader-header .book-title {
        font-size: 12px;
    }

    .reader-header .chapter-title {
        display: none;
    }

    .nav-btn {
        font-size: 12px;
    }

    .word-popup {
        bottom: 170px;
        max-width: 340px;
    }

    .popup-word {
        font-size: 24px;
    }
}

@media (max-width: 480px) {
    :root {
        --word-margin-x: 3px;
        --band-top: 0.45em;
        --highlight-offset-y: -2px;
        --band-radius: 4px;
        --underline-thickness: 6px;
    }

    .content-area {
        padding: 16px 8px;
        padding-bottom: 190px;
    }

    .japanese-text {
        font-size: 16px;
        line-height: 1.9;
    }

    .word {
        margin: 2px 3px;
        padding: 2px 4px;
        font-size: 15px;
        border-radius: 4px;
    }

    .sentence-block {
        padding: 12px;
        margin-bottom: 10px;
        border-radius: 8px;
    }

    .translation-text {
        font-size: 14px;
        padding-left: 12px;
    }

    /* 小屏播放器优化 */
    .audio-player-wrapper {
        padding: 8px 12px;
        padding-bottom: calc(8px + env(safe-area-inset-bottom, 0px));
    }

    .player-nav-row {
        margin-bottom: 6px;
    }

    .nav-btn {
        font-size: 11px;
    }

    .audio-player {
        gap: 8px;
    }

    .progress-wrapper {
        margin-bottom: 6px;
        font-size: 11px;
    }

    .play-btn {
        width: 44px;
        height: 44px;
    }

    .play-btn svg {
        width: 18px;
        height: 18px;
    }

    .player-controls {
        gap: 5px;
    }

    .control-btn {
        width: 30px;
        height: 30px;
    }

    .control-btn svg {
        width: 14px;
        height: 14px;
    }

    .speed-select {
        width: 38px;
        height: 30px;
        font-size: 10px;
        padding: 0 4px;
    }

    /* 与 mirra.css 保持一致的 ruby 布局，确保高亮框位置稳定 */
    ruby {
        display: inline-flex;
        flex-direction: column;
        align-items: center;
        line-height: 1.1;
    }

    ruby rt {
        font-size: 0.6em;
        line-height: 1;
        margin-top: -2.5em;
        transform: none !important;
    }

    .word-popup {
        bottom: 160px;
        max-width: 300px;
    }

    .popup-header {
        padding: 16px;
    }

    .popup-word {
        font-size: 22px;
    }

    .popup-body {
        padding: 16px;
    }

    .popup-meaning {
        font-size: 16px;
    }
}

/* ========================================
   图书馆页面样式
   ======================================== */
.library-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    background: var(--bg-color);
    min-height: calc(100vh - 200px);
}

.library-header {
    text-align: center;
    margin-bottom: 40px;
}

.library-header h1 {
    font-size: 28px;
    color: var(--text-color);
    margin-bottom: 8px;
}

.library-header .subtitle {
    color: var(--muted-color);
    font-size: 16px;
}

.filter-bar {
    display: flex;
    gap: 12px;
    margin-bottom: 32px;
    flex-wrap: wrap;
}

.filter-select,
.search-input {
    padding: 10px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    background: var(--paper-color);
    color: var(--text-color);
}

.search-input {
    flex: 1;
    max-width: 300px;
    min-width: 200px;
}

/* 正在阅读 */
.reading-now {
    margin-bottom: 48px;
}

.reading-now h2 {
    font-size: 18px;
    margin-bottom: 16px;
    color: var(--text-color);
}

.current-book-card {
    display: flex;
    gap: 24px;
    padding: 24px;
    background: var(--paper-color);
    border-radius: 12px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    border: 1px solid var(--border-color);
}

.book-cover-large {
    width: 120px;
    height: 170px;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    flex-shrink: 0;
}

.current-book-card .book-info {
    flex: 1;
}

.current-book-card .book-info h3 {
    font-size: 20px;
    margin-bottom: 4px;
    color: var(--text-color);
}

.current-book-card .author {
    color: var(--muted-color);
    margin-bottom: 12px;
    font-size: 14px;
}

.current-book-card .progress {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 8px;
}

.progress-bar {
    width: 200px;
    height: 6px;
    background: var(--border-color);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 16px;
}

.progress-fill {
    height: 100%;
    background: var(--accent-color);
    border-radius: 3px;
    transition: width 0.3s;
}

.btn-continue {
    display: inline-block;
    padding: 10px 20px;
    background: var(--accent-color);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-size: 14px;
    transition: opacity 0.2s;
}

.btn-continue:hover {
    opacity: 0.9;
    color: white;
}

/* 图书网格 */
.all-books h2 {
    font-size: 18px;
    margin-bottom: 24px;
    color: var(--text-color);
}

.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 24px;
}

.book-card {
    background: var(--paper-color);
    border-radius: 12px;
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid var(--border-color);
}

.book-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

.book-card a {
    text-decoration: none;
    color: inherit;
}

.cover-wrapper {
    position: relative;
    aspect-ratio: 3/4;
    overflow: hidden;
}

.book-cover {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.difficulty-badge {
    position: absolute;
    top: 8px;
    right: 8px;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 500;
    background: rgba(255, 255, 255, 0.9);
}

.difficulty-badge.N5 { color: #4CAF50; }
.difficulty-badge.N4 { color: #8BC34A; }
.difficulty-badge.N3 { color: #FFC107; }
.difficulty-badge.N2 { color: #FF9800; }
.difficulty-badge.N1 { color: #F44336; }

.book-meta {
    padding: 16px;
}

.book-title {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 4px;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    color: var(--text-color);
}

.book-author {
    font-size: 13px;
    color: var(--muted-color);
    margin-bottom: 4px;
}

.book-chapters {
    font-size: 12px;
    color: var(--text-light);
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--muted-color);
}

/* ========================================
   隐藏平假名功能
   ======================================== */
body.hide-furigana rt,
.reader-container.hide-furigana rt {
    display: none !important;
}

/* ========================================
   生词标红功能
   ======================================== */
.word.vocab-word,
.word.vocab-word .word-text {
    color: #ef4444 !important;
}

.word.vocab-word::after {
    content: "";
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: #ef4444;
    border-radius: 1px;
}

/* ========================================
   收藏按钮样式
   ======================================== */
#btn-favorite.is-collected svg {
    fill: #ef4444;
    stroke: #ef4444;
}

/* ========================================
   句子操作按钮
   ======================================== */
.sentence-actions {
    display: flex;
    gap: 8px;
    margin-top: 8px;
    opacity: 0;
    transition: opacity 0.2s;
}

.sentence-block:hover .sentence-actions {
    opacity: 1;
}

.sentence-action-btn {
    background: var(--paper-color);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 4px 8px;
    font-size: 12px;
    cursor: pointer;
    color: var(--muted-color);
    display: flex;
    align-items: center;
    gap: 4px;
    transition: all 0.2s;
}

.sentence-action-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
    background: rgba(139, 115, 85, 0.05);
}

/* ========================================
   设置面板扩展样式
   ======================================== */
.setting-section {
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.setting-section:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.setting-section-title {
    font-size: 13px;
    font-weight: 600;
    color: var(--muted-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 16px;
}

/* 开关按钮样式 */
.setting-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    user-select: none;
}

.setting-toggle input[type="checkbox"] {
    display: none;
}

.toggle-slider {
    width: 44px;
    height: 24px;
    background: var(--border-color);
    border-radius: 12px;
    position: relative;
    transition: background 0.3s;
}

.toggle-slider::after {
    content: "";
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    transition: transform 0.3s;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.setting-toggle input:checked + .toggle-slider {
    background: var(--accent-color);
}

.setting-toggle input:checked + .toggle-slider::after {
    transform: translateX(20px);
}

/* ========================================
   Modal 弹窗样式
   ======================================== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal.hidden {
    display: none;
}

.modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1;
}

.modal-content {
    position: relative;
    z-index: 2;
    background: var(--paper-color);
    border-radius: 16px;
    max-width: 500px;
    width: 100%;
    max-height: 80vh;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: modalSlideIn 0.3s ease-out;
    display: flex;
    flex-direction: column;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: scale(0.95) translateY(20px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    margin: 0;
    font-size: 18px;
    font-weight: 600;
    color: var(--text-color);
}

.btn-close-modal {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--muted-color);
    padding: 0;
    line-height: 1;
    transition: color 0.2s;
}

.btn-close-modal:hover {
    color: var(--text-color);
}

.modal-body {
    padding: 20px;
    overflow-y: auto;
    flex: 1;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    padding: 16px 20px;
    border-top: 1px solid var(--border-color);
}

.btn-primary {
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: opacity 0.2s;
}

.btn-primary:hover {
    opacity: 0.9;
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-secondary {
    background: var(--border-color);
    color: var(--text-color);
    border: none;
    border-radius: 8px;
    padding: 10px 20px;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.2s;
}

.btn-secondary:hover {
    background: var(--muted-color);
    color: white;
}

/* ========================================
   AI 分析弹窗样式
   ======================================== */
.ai-analysis-sentence {
    background: var(--highlight-color);
    padding: 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 18px;
    line-height: 1.8;
    font-family: 'Noto Serif JP', serif;
}

.ai-loading {
    text-align: center;
    padding: 40px 20px;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top-color: var(--accent-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto 16px;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.ai-loading p {
    color: var(--muted-color);
    font-size: 14px;
}

.ai-analysis-result {
    /* Container for analysis result sections */
}

.analysis-section {
    margin-bottom: 20px;
}

.analysis-section:last-child {
    margin-bottom: 0;
}

.analysis-section h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.analysis-section ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.analysis-section li {
    padding: 10px;
    background: var(--bg-color);
    border-radius: 8px;
    margin-bottom: 8px;
    font-size: 14px;
    line-height: 1.6;
}

.analysis-section li:last-child {
    margin-bottom: 0;
}

.analysis-section li strong {
    color: var(--accent-color);
}

.analysis-section p {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-light);
}

.ai-error {
    background: #fef2f2;
    border: 1px solid #fecaca;
    padding: 16px;
    border-radius: 8px;
    text-align: center;
}

.ai-error p {
    color: #dc2626;
    margin: 0;
}

/* AI 分析元素隐藏状态 */
.ai-loading.hidden,
.ai-analysis-result.hidden,
.ai-error.hidden {
    display: none;
}

/* 句子翻译 */
.sentence-translation {
    font-size: 16px;
    color: var(--text-color);
    padding: 12px 16px;
    background: var(--highlight-color);
    border-radius: 8px;
    margin-bottom: 20px;
    border-left: 4px solid var(--accent-color);
}

/* 语法等级标签 */
.grammar-level {
    display: inline-block;
    background: var(--accent-color);
    color: #fff;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
    margin-left: 8px;
}

/* 跟读分段 */
.shadowing-text {
    font-size: 16px;
    letter-spacing: 0.5px;
    color: var(--text-color);
    background: var(--bg-color);
    padding: 12px 16px;
    border-radius: 8px;
}

/* ========================================
   问题反馈弹窗样式
   ======================================== */
.feedback-intro {
    color: var(--text-light);
    margin-bottom: 16px;
    font-size: 14px;
}

.feedback-types {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    margin-bottom: 20px;
}

.feedback-type-option {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 14px;
}

.feedback-type-option:hover {
    border-color: var(--accent-color);
}

.feedback-type-option input {
    accent-color: var(--accent-color);
}

.feedback-type-option input:checked + span {
    color: var(--accent-color);
    font-weight: 500;
}

.feedback-description label {
    display: block;
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 8px;
}

.feedback-description textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    resize: vertical;
    background: var(--paper-color);
    color: var(--text-color);
    font-family: inherit;
}

.feedback-description textarea:focus {
    outline: none;
    border-color: var(--accent-color);
}

/* ========================================
   循环按钮和弹出面板 - 现代风格
   ======================================== */
.loop-control-wrapper {
    position: relative;
}

#btn-loop.active {
    background: #fef3c7;
    border-color: #f59e0b;
    color: #b45309;
    box-shadow: 0 6px 16px rgba(245, 158, 11, 0.2);
}

.loop-popover {
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    margin-bottom: 12px;
    z-index: 200;
}

.loop-popover.hidden {
    display: none;
}

.loop-popover-content {
    background: var(--paper-color);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 14px 18px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.18);
    min-width: 180px;
}

/* 弹出箭头 */
.loop-popover-content::after {
    content: "";
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    border-top: 8px solid var(--paper-color);
}

.loop-option {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 0;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-color);
}

.loop-option:first-child {
    padding-top: 0;
}

.loop-option:last-child {
    padding-bottom: 0;
}

.loop-option + .loop-option {
    border-top: 1px solid var(--border-color);
}

/* 现代开关样式 */
.toggle-switch {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
    cursor: pointer;
}

.toggle-switch input {
    display: none;
}

.toggle-slider-small {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: #e5e7eb;
    border-radius: 24px;
    transition: all 0.3s ease;
}

.toggle-slider-small::after {
    content: "";
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    transition: transform 0.3s ease;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.toggle-switch input:checked + .toggle-slider-small {
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
}

.toggle-switch input:checked + .toggle-slider-small::after {
    transform: translateX(20px);
}

@media (max-width: 576px) {
    .current-book-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .progress-bar {
        width: 100%;
        max-width: 200px;
        margin-left: auto;
        margin-right: auto;
    }

    .book-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 16px;
    }
}