/* 全局样式 */
:root {
    /* 主色调 */
    --color-primary: #1a365d;
    --color-primary-dark: #0f2942;
    --color-primary-light: #2c4c7c;
    
    /* 强调色 */
    --color-accent: #3498db;
    --color-accent-light: #5dade2;
    
    /* 中性色调 */
    --color-background: #f9fafb;
    --color-background-dark: #0f172a;
    --color-text: #1a202c;
    --color-text-light: #718096;
    --color-text-lighter: #a0aec0;
    --color-border: #e2e8f0;
    
    /* 功能色 */
    --color-success: #0d9488;
    --color-danger: #e53e3e;
    --color-warning: #f59e0b;
    --color-info: #3182ce;
    
    /* 阴影效果 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.09);
    
    /* 高亮颜色 */
    --color-highlight: rgba(49, 130, 206, 0.15);
    --color-highlight-hover: rgba(49, 130, 206, 0.25);
    --color-sentence-highlight: rgba(49, 130, 206, 0.15);
    --color-sentence-highlight-hover: rgba(49, 130, 206, 0.25);
    --color-underline: #4a5568;
    
    /* 工具提示颜色 */
    --color-tooltip-bg: #ffffff;
    --color-tooltip-header: #f8f9fa;
    --color-tooltip-phonetic: #3182ce;
    --color-tooltip-close: #a0aec0;
    --color-tooltip-close-hover: #1a202c;
    
    /* 动画时间 */
    --transition-fast: 200ms;
    --transition-normal: 300ms;
    --transition-slow: 400ms;
    
    /* 尺寸变量 */
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.375rem;
    --border-radius-lg: 0.5rem;
    --border-radius-xl: 0.75rem;
    --border-radius-full: 9999px;
    
    /* 间距 */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* 布局 */
    --content-width-sm: 640px;
    --content-width-md: 768px;
    --content-width-lg: 1024px;
    --content-width-xl: 1280px;
    --pdf-width: 595px;
    
    /* 字体大小 */
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* 字体粗细 */
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* 波浪线样式 */
    --wave-line-height: 3px;
    --wave-line-width: 1.5px;
    --wave-background-size: 10px 3px;
    --wave-color: #4a5568;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    -webkit-tap-highlight-color: transparent; /* 移除移动设备上的点击高亮 */
    touch-action: manipulation; /* 优化触摸体验，减少延迟 */
}

/* 防止滚动条引起的页面跳动 */
html {
    overflow-y: scroll; /* 强制显示滚动条 */
    scrollbar-width: thin; /* Firefox */
    scrollbar-gutter: stable; /* 保持空间稳定，防止滚动条出现/消失时布局变化 */
    --current-zoom: 1;
}

html[data-current-zoom-level] {
    --current-zoom: attr(data-current-zoom-level number, 1);
}

/* 为WebKit浏览器设置固定宽度的滚动条 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 4px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Microsoft YaHei", sans-serif;
    background-color: var(--color-background);
    color: var(--color-text);
    line-height: 1.5;
    font-size: var(--font-size-md);
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    padding-right: 0; /* 防止滚动条导致的内容位移 */
    overflow-y: auto; /* 确保内容可以滚动 */
}

/* 添加新的body修饰类，用于处理移动导航 */
body.nav-open {
    overflow: hidden;
}

/* 添加英文字体规则 */
html :lang(en), 
html .english-text, 
html #tooltip-word,
html #tooltip-translation,
html .tooltip-extra,
html .word-tooltip {
    font-family: 'Times New Roman', 'Georgia', 'Cambria', Times, serif;
}

body.pdf-view-body {
    padding: 0;
    margin: 0;
    overflow-x: hidden; /* 修改：限制水平方向溢出 */
    overflow-y: visible; /* 修改：允许垂直方向由浏览器控制滚动 */
    background-color: #ffffff; /* 白色背景 */
    /* 禁用文本选择 */
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    /* 设置默认光标为普通箭头，防止显示文本光标 */
    cursor: default;
}

/* 导航栏样式 - 重新设计 */
.main-header {
    background-color: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
    position: sticky;
    top: 0;
    z-index: 100;
    width: 100%;
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    will-change: transform; /* 优化性能，使用GPU加速 */
    transform: translateZ(0); /* 强制GPU加速，减少抖动 */
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
    padding: 0;
    width: 100%;
}

.logo {
    color: var(--color-primary);
    font-weight: var(--font-weight-semibold);
    font-size: 1.25rem;
    text-decoration: none;
    transition: all 0.2s ease;
    white-space: nowrap;
    letter-spacing: -0.01em;
    padding: var(--spacing-md) 0;
}

.logo:hover {
    color: var(--color-accent);
    transform: translateY(-1px);
}

.main-nav {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    flex: 1;
}

.nav-links {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 2.5rem;
    white-space: nowrap;
    height: 100%;
}

.nav-links li {
    height: 100%;
    display: flex;
    align-items: center;
    padding: 0 0.15rem;
}

.nav-item {
    position: relative;
    color: var(--color-text);
    text-decoration: none;
    font-size: 0.95rem;
    padding: 0.5rem 0;
    font-weight: var(--font-weight-medium);
    transition: transform 0.25s cubic-bezier(0.165, 0.84, 0.44, 1),
                color 0.25s ease,
                font-weight 0.25s ease,
                text-shadow 0.25s ease;
    display: inline-block;
    letter-spacing: 0.01em;
    transform-origin: center;
    will-change: transform;
}

.nav-item::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: width 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), left 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    opacity: 0;
    transform-origin: center;
}

.nav-item:hover {
    color: var(--color-accent);
    transform: scale(1.05);
    font-weight: var(--font-weight-semibold);
}

.nav-item:hover::after {
    width: 100%;
    left: 0;
    opacity: 1;
}

.nav-item.active {
    color: var(--color-accent);
    font-weight: var(--font-weight-bold);
    position: relative;
    text-shadow: 0 0 0.5px var(--color-accent), 0 0 1px rgba(52, 152, 219, 0.1);
}

.nav-item.active::after {
    width: 100%;
    left: 0;
    opacity: 1;
    height: 2.5px;
    background-color: var(--color-accent);
    box-shadow: 0 0 4px rgba(52, 152, 219, 0.3);
}

/* 移动端汉堡菜单按钮 */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 20px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    margin-left: 1rem;
    z-index: 1000;
}

.mobile-menu-toggle span {
    display: block;
    height: 2px;
    width: 100%;
    background-color: var(--color-text);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* 移动端导航样式 */
@media (max-width: 480px) {
    .mobile-menu-toggle {
        display: flex;
    }
    
    .nav-links {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: white;
        padding: 0;
        box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
        gap: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
        z-index: 99;
    }
    
    .nav-links.active {
        max-height: 300px;
        border-bottom: 1px solid var(--color-border);
    }
    
    .nav-links li {
        width: 100%;
        height: auto;
        border-bottom: 1px solid var(--color-border);
    }
    
    .nav-links li:last-child {
        border-bottom: none;
    }
    
    .nav-item {
        display: block;
        padding: 1rem 2rem;
        font-size: 1rem;
        width: 100%;
        transform: none;
    }
    
    .nav-item:hover {
        transform: none;
        background-color: rgba(52, 152, 219, 0.05);
    }
    
    .nav-item:active {
        background-color: rgba(52, 152, 219, 0.15);
        transition: background-color 0.1s ease;
    }
    
    .nav-item::after {
        display: none;
    }
    
    .nav-item.active {
        background-color: rgba(52, 152, 219, 0.1);
        border-left: 3px solid var(--color-accent);
        padding-left: calc(2rem - 3px);
    }
    
    .nav-item.active:active {
        background-color: rgba(52, 152, 219, 0.2);
    }
    
    .mobile-menu-toggle.active span:nth-child(1) {
        transform: translateY(9px) rotate(45deg);
    }
    
    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .mobile-menu-toggle.active span:nth-child(3) {
        transform: translateY(-9px) rotate(-45deg);
    }
}

/* 主要内容区域调整，让内容不被导航栏遮挡 */
.main-content {
    padding-top: 2rem;
    min-height: calc(100vh - 60px - 60px); /* viewport高度减去header和footer高度 */
}

footer {
    background-color: #fff;
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-md);
    margin-top: var(--spacing-xl);
    text-align: center;
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
}

.footer-links {
    margin-top: 0.5rem;
    font-size: 0.8rem;
}

footer a {
    color: var(--color-text-light);
    text-decoration: none;
    transition: color var(--transition-fast) ease;
}

footer a:hover {
    color: var(--color-accent);
    text-decoration: underline;
}

.beian-text {
    font-size: 0.8rem;
    color: var(--color-text-lighter);
}

.beian-text a {
    color: var(--color-text-lighter);
}

.beian-text a:hover {
    color: var(--color-accent);
}

.footer-legal {
    font-size: 0.75rem;
    color: var(--color-text-lighter);
    margin-top: 0.5rem;
    opacity: 0.7;
    text-align: center;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    padding-top: 0.5rem;
    margin-bottom: 0;
}

.footer-legal a {
    color: inherit;
    text-decoration: none;
    transition: opacity 0.2s ease;
}

.footer-legal a:hover {
    opacity: 1;
    color: var(--color-text-light);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* 极简页脚设计 */
.minimal-footer {
    padding: 10px 0;
    margin-top: 2rem;
    background-color: transparent;
    border-top: none;
}

.legal-info {
    font-size: 0.65rem;
    color: rgba(0, 0, 0, 0.15);
    text-align: center;
    margin: 0;
    letter-spacing: 0.02em;
    transition: opacity 0.2s ease;
}

.legal-info:hover {
    opacity: 0.8;
    color: rgba(0, 0, 0, 0.3);
}

.legal-info .separator {
    margin: 0 4px;
    opacity: 0.5;
}

.legal-info a.beian {
    color: inherit;
    text-decoration: none;
    padding: 0 4px;
}

.legal-info .copyright,
.legal-info .version {
    opacity: 0.7;
}

.legal-info a.beian:hover {
    text-decoration: none;
    opacity: 1;
}

@media (max-width: 768px) {
    .legal-info {
        font-size: 0.6rem;
    }
    
    .footer-legal {
        font-size: 0.7rem;
        margin-top: 0.75rem;
    }
}

h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    line-height: 1.2;
}

h1 {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
}

h2 {
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-semibold);
}

h3 {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-semibold);
}

a {
    color: var(--color-link);
    text-decoration: none;
    transition: color var(--transition-fast) ease;
}

a:hover {
    color: var(--color-link-hover);
}

.container {
    width: 100%;
    max-width: var(--content-width-xl);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--border-radius-md);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-md);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    transition: all var(--transition-fast) ease;
    text-align: center;
    line-height: 1.5;
    box-shadow: var(--shadow-sm);
}

.btn:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

.btn-large {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-lg);
    border-radius: var(--border-radius-lg);
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-sm);
}

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

.btn-danger:hover {
    background-color: #b91c1c;
}

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

.btn-success:hover {
    background-color: #047857;
}

.btn-secondary {
    background-color: white;
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

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

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

.btn-accent:hover {
    background-color: #b45309;
}

/* 警告框 */
.alert {
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    border-radius: var(--border-radius-md);
    font-weight: var(--font-weight-medium);
}

.alert-danger {
    background-color: #fee2e2;
    color: #b91c1c;
    border: 1px solid #fecaca;
}

.alert-success {
    background-color: #d1fae5;
    color: #047857;
    border: 1px solid #a7f3d0;
}

.alert-warning {
    background-color: #fef3c7;
    color: #b45309;
    border: 1px solid #fde68a;
}

.alert-info {
    background-color: #dbeafe;
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

/* 加载动画 */
.loading-spinner {
    display: inline-block;
    width: 1.5rem;
    height: 1.5rem;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

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

/* 过渡动画类 */
.fade-enter {
    opacity: 0;
}

.fade-enter-active {
    opacity: 1;
    transition: opacity var(--transition-normal) ease;
}

.fade-exit {
    opacity: 1;
}

.fade-exit-active {
    opacity: 0;
    transition: opacity var(--transition-normal) ease;
}

.slide-in {
    animation: slideIn var(--transition-normal) ease forwards;
}

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

/* 媒体查询 */
@media (max-width: 768px) {
    .main-nav {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .nav-brand {
        margin-bottom: var(--spacing-sm);
    }
    
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--spacing-sm);
    }
    
    .nav-auth {
        margin-top: var(--spacing-sm);
    }
    
    header {
        padding: var(--spacing-sm);
    }
    
    main {
        padding: var(--spacing-md);
    }
    
    h1 {
        font-size: var(--font-size-2xl);
    }
    
    h2 {
        font-size: var(--font-size-xl);
    }
    
    h3 {
        font-size: var(--font-size-lg);
    }
    
    .btn-large {
        padding: var(--spacing-sm) var(--spacing-lg);
        font-size: var(--font-size-md);
    }
}

/* 导航链接项间距微调，使其更美观 */
@media (min-width: 769px) {
    .nav-links {
        gap: 2rem;
    }
    
    .nav-item {
        padding: 0.5rem 0.5rem;
    }
}

/* 移动导航时的内容区域调整 */
@media (max-width: 768px) {
    .nav-open .main-content {
        filter: blur(3px);
        pointer-events: none;
    }
    
    .main-header {
        backdrop-filter: none;
        -webkit-backdrop-filter: none;
    }
    
    .main-content {
        padding-top: 1.5rem;
        min-height: calc(100vh - 60px - 60px);
    }
    
    .mobile-menu-toggle span {
        transition: transform 0.25s ease, opacity 0.15s ease;
    }
}

/* 平板设备优化 */
@media (min-width: 769px) and (max-width: 1024px) {
    .header-inner {
        height: 60px;
    }
    
    .logo {
        font-size: 1.2rem;
    }
    
    .nav-links {
        gap: 1.5rem;
    }
    
    .nav-item {
        font-size: 0.9rem;
        padding: 0.5rem 0.35rem;
    }
    
    .nav-item:hover {
        transform: scale(1.03);
    }
    
    .nav-item.active:hover {
        transform: scale(1.03);
    }
}

/* PDF查看器样式 */
#pdf-viewer {
    width: 100%;
    max-width: 100%;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #ffffff;
    height: auto;
    position: relative;
    padding-bottom: var(--spacing-3xl);
    transition: padding var(--transition-normal) ease;
}

/* 添加.pdf-viewer类的样式，确保宽度限制 */
.pdf-viewer {
    width: 100%;
    max-width: var(--pdf-width);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.pdf-page {
    width: 100%;
    max-width: var(--pdf-width);
    margin-bottom: var(--spacing-md);
    position: relative;
    box-shadow: var(--shadow-lg);
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    background-color: white;
    transition: all var(--transition-normal) ease;
}

.pdf-page:last-child {
    margin-bottom: 0;
}

.pdf-page img {
    display: block;
    width: 100%;
    height: auto;
    user-select: none;
    pointer-events: none;
}

.word-clickable-area {
    position: absolute;
    cursor: pointer;
    z-index: 2;
    transition: background-color var(--transition-fast) ease;
    border-radius: 1px;
}

.word-clickable-area:hover {
    background-color: var(--color-highlight);
}

.highlight-word {
    position: absolute;
    pointer-events: none;
    background-color: var(--color-highlight);
    border-radius: 1px;
    transition: background-color var(--transition-fast) ease;
    z-index: 1;
}

.highlight-word:hover {
    background-color: var(--color-highlight-hover);
}

/* 激活状态的单词高亮 */
.pdf-viewer .highlight-word-active,
.pdf-page .highlight-word-active {
    background-color: rgba(255, 215, 0, 0.6); /* 金黄色高亮 */
    z-index: 2; /* 确保在其他高亮上层 */
    box-shadow: 0 0 3px rgba(0, 0, 0, 0.2); /* 轻微阴影增强视觉效果 */
}

.word-viewed {
    position: relative;
}

/* 新的波浪线样式 */
.wavy-underline {
    position: absolute;
    background-repeat: repeat-x;
    pointer-events: none;
    z-index: 3;
    height: 3px;
    /* 波浪线不再通过伪元素实现，而是通过JS动态创建的独立元素 */
}

/* 不同设备类型的适配 */
html[data-device-type="tablet"] .wavy-underline {
    height: 2.5px;
}

html[data-device-type="mobile"] .wavy-underline {
    height: 2px;
}

html.is-high-dpi .wavy-underline {
    height: 2px;
    background-size: 8px 2px;
}

/* 调试辅助样式 */
.element-debug-box {
    position: absolute;
    border: 1px solid rgba(255, 0, 0, 0.5);
    background-color: rgba(255, 0, 0, 0.1);
    pointer-events: none;
    z-index: 9999;
}

/* 旧样式清理 - 删除可能与新实现冲突的样式 */
@media (pointer: fine), (pointer: coarse) {
    .word-viewed {
        --wave-y-offset: 0; /* 重置变量 */
    }
}

.touch-viewed::after,
.large-screen-viewed::after,
.small-screen-viewed::after,
html.is-touch-device .word-viewed::after,
html.is-tablet .word-viewed::after,
.desktop-mode-enforced .word-viewed::after {
    display: none; /* 确保所有旧实现都被禁用 */
}

/* 全局缩放状态标记 */
html {
    --current-zoom: 1;
}

html[data-current-zoom-level] {
    --current-zoom: attr(data-current-zoom-level number, 1);
}

/* 预设波浪线配置 */
:root {
    --wave-line-height: 3px;
    --wave-line-width: 1.5px;
    --wave-background-size: 10px 3px;
    --wave-color: #4a5568;
}

/* 高DPI屏幕 */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    :root {
        --wave-line-height: 2px;
        --wave-line-width: 1px;
        --wave-background-size: 8px 2px;
    }
}

.highlight-word.sentence-highlight {
    background-color: var(--color-sentence-highlight);
}

.highlight-word.sentence-highlight:hover {
    background-color: var(--color-sentence-highlight-hover);
}

/* 词汇提示框样式 */
.word-tooltip {
    position: fixed;
    background-color: var(--color-tooltip-bg);
    width: 320px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    z-index: 1000;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity var(--transition-normal) ease, transform var(--transition-normal) ease;
    max-height: 400px;
    display: none;
    border: 1px solid var(--color-border);
}

/* 工具提示箭头基础样式 */
.tooltip-arrow {
    position: absolute;
    width: 0;
    height: 0;
    border-style: solid;
    pointer-events: none;
    z-index: 1001;
    display: block;
}

/* 左侧箭头 */
.tooltip-arrow-left {
    left: -8px;
    top: 50%;
    transform: translateY(-50%);
    border-width: 8px 8px 8px 0;
    border-color: transparent var(--color-tooltip-bg) transparent transparent;
    filter: drop-shadow(-2px 0px 2px rgba(0, 0, 0, 0.1));
}

/* 右侧箭头 */
.tooltip-arrow-right {
    right: -8px;
    top: 50%;
    transform: translateY(-50%);
    border-width: 8px 0 8px 8px;
    border-color: transparent transparent transparent var(--color-tooltip-bg);
    filter: drop-shadow(2px 0px 2px rgba(0, 0, 0, 0.1));
}

/* 顶部箭头 */
.tooltip-arrow-top {
    top: -8px;
    left: 50%;
    transform: translateX(-50%);
    border-width: 0 8px 8px 8px;
    border-color: transparent transparent var(--color-tooltip-bg) transparent;
    filter: drop-shadow(0px -2px 2px rgba(0, 0, 0, 0.08));
}

/* 底部箭头 */
.tooltip-arrow-bottom {
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    border-width: 8px 8px 0 8px;
    border-color: var(--color-tooltip-bg) transparent transparent transparent;
    filter: drop-shadow(0px 2px 2px rgba(0, 0, 0, 0.08));
}

/* 角落箭头 */
.tooltip-arrow-top-left {
    top: -8px;
    left: 16px;
    border-width: 0 8px 8px 8px;
    border-color: transparent transparent var(--color-tooltip-bg) transparent;
    filter: drop-shadow(0px -2px 2px rgba(0, 0, 0, 0.08));
}

.tooltip-arrow-top-right {
    top: -8px;
    right: 16px;
    border-width: 0 8px 8px 8px;
    border-color: transparent transparent var(--color-tooltip-bg) transparent;
    filter: drop-shadow(0px -2px 2px rgba(0, 0, 0, 0.08));
}

/* 工具提示状态 */
.word-tooltip.visible {
    opacity: 1;
    transform: translateY(0);
    display: block;
}

.tooltip-header {
    display: flex;
    align-items: center;
    padding: var(--spacing-md);
    background-color: var(--color-tooltip-header);
    border-bottom: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg) var(--border-radius-lg) 0 0;
}

#tooltip-word {
    font-size: var(--font-size-xl);
    font-weight: var(--font-weight-bold);
    margin-right: var(--spacing-sm);
    color: var(--color-text);
}

#tooltip-phonetic {
    font-size: var(--font-size-md);
    font-weight: var(--font-weight-normal);
    color: var(--color-tooltip-phonetic);
    font-style: italic;
    margin-right: auto;
}

.tooltip-close-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-tooltip-close);
    font-size: var(--font-size-xl);
    padding: 0;
    margin-left: var(--spacing-sm);
    line-height: 1;
    transition: color var(--transition-fast) ease;
}

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

.tooltip-content {
    padding: var(--spacing-md);
    overflow-y: auto;
    max-height: 300px;
}

.tooltip-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xs);
    font-weight: var(--font-weight-medium);
}

.tooltip-translation-section,
.tooltip-extra-section {
    margin-bottom: var(--spacing-md);
}

.tooltip-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tag {
    background-color: var(--color-background);
    border-radius: var(--border-radius-full);
    padding: 2px 8px;
    font-size: var(--font-size-xs);
}

.tooltip-tags-section {
    margin-bottom: var(--spacing-md);
}

.tooltip-example-section {
    margin-bottom: var(--spacing-md);
}

#tooltip-example {
    font-style: italic;
    color: var(--color-text-light);
}

.tooltip-extra {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    margin-top: var(--spacing-xs);
    font-style: italic;
}

#tooltip-translation {
    font-size: var(--font-size-md);
    line-height: 1.5;
    color: var(--color-text);
}

/* 浮动返回按钮 */
.back-btn-corner {
    position: fixed;
    top: var(--spacing-md);
    left: var(--spacing-md);
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--border-radius-full);
    background-color: rgba(255, 255, 255, 0.8);
    color: var(--color-text);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xl);
    text-decoration: none;
    z-index: 100;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    transition: all var(--transition-fast) ease;
    border: none;
    cursor: pointer;
}

.back-btn-corner:hover {
    background-color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* 缩放控制 */
.zoom-controls {
    position: fixed;
    top: var(--spacing-md);
    right: var(--spacing-md);
    display: flex;
    align-items: center;
    background-color: rgba(255, 255, 255, 0.8);
    border-radius: var(--border-radius-full);
    padding: var(--spacing-xs) var(--spacing-sm);
    z-index: 100;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    transition: all var(--transition-fast) ease;
}

.zoom-controls:hover {
    background-color: white;
    box-shadow: var(--shadow-lg);
}

.zoom-btn {
    background: none;
    border: none;
    width: 2rem;
    height: 2rem;
    border-radius: var(--border-radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-lg);
    color: var(--color-text);
    cursor: pointer;
    transition: all var(--transition-fast) ease;
}

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

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

.zoom-level {
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    padding: 0 var(--spacing-sm);
    color: var(--color-text);
    min-width: 4rem;
    text-align: center;
}

/* 音频按钮 */
.tooltip-audio-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-tooltip-phonetic);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2rem;
    height: 2rem;
    border-radius: var(--border-radius-full);
    transition: all var(--transition-fast) ease;
}

.tooltip-audio-btn:hover {
    background-color: var(--color-background);
}

/* 移除标记按钮 */
.tooltip-remove-mark-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-tooltip-close);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2rem;
    height: 2rem;
    border-radius: var(--border-radius-full);
    transition: all var(--transition-fast) ease;
    margin-left: var(--spacing-xs);
}

.tooltip-remove-mark-btn:hover {
    background-color: var(--color-background);
    color: var(--color-tooltip-close-hover);
}

/* 卡片列表 */
.pdf-list {
    list-style: none;
    margin: var(--spacing-xl) 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.pdf-list li {
    margin: 0;
    padding: 0;
    transition: all var(--transition-fast) ease;
}

.pdf-card {
    display: block;
    background-color: white;
    border-radius: var(--border-radius-md);
    box-shadow: 
        0 1px 3px rgba(0,0,0,0.02),
        0 4px 6px rgba(0,0,0,0.03),
        0 10px 20px rgba(0,0,0,0.04);
    overflow: hidden;
    height: 100%;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid var(--color-border);
}

.pdf-card:hover {
    transform: translateY(-3px);
    box-shadow: 
        0 2px 4px rgba(0,0,0,0.03),
        0 8px 16px rgba(0,0,0,0.05),
        0 16px 32px rgba(0,0,0,0.06);
    text-decoration: none;
    border-color: var(--color-accent);
}

.pdf-card-header {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    background-color: var(--color-tooltip-header);
}

.pdf-card-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    margin: 0;
    color: var(--color-primary);
}

.pdf-card-body {
    padding: var(--spacing-md);
}

.pdf-card-info {
    margin-top: var(--spacing-xs);
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
}

.year-tag {
    display: inline-block;
    background-color: var(--color-primary-light);
    color: white;
    font-size: var(--font-size-xs);
    padding: 2px 8px;
    border-radius: var(--border-radius-full);
    margin-right: var(--spacing-xs);
}

/* 空状态 */
.no-files {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--color-text-light);
    background-color: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
}

/* 首页特殊样式 */
.hero-section {
    padding: var(--spacing-3xl) 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: calc(100vh - 200px);
    text-align: center;
}

.hero-content {
    max-width: 720px;
    margin: 0 auto;
    animation: fadeIn 0.8s ease-out forwards;
}

.hero-content h1 {
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    position: relative;
    padding-bottom: var(--spacing-md);
}

.hero-content h1::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    border-radius: 3px;
    animation: gradientFlow 3s ease infinite;
    background-size: 200% 200%;
}

.tagline {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

.tagline span {
    color: var(--color-text-light);
    font-size: var(--font-size-lg);
    padding: var(--spacing-xs) 0;
    transition: transform 0.3s ease, color 0.3s ease;
}

.tagline span:hover {
    transform: translateY(-2px);
    color: var(--color-primary);
}

.tagline span:nth-child(1),
.tagline span:nth-child(3) {
    color: var(--color-accent);
    font-weight: var(--font-weight-medium);
}

.tagline span:last-child {
    font-style: italic;
    opacity: 0.9;
}

.tagline::after {
    content: '';
    width: 40px;
    height: 2px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    margin-top: var(--spacing-sm);
    border-radius: 2px;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.btn-accent {
    background-color: var(--color-accent);
    color: white;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-medium);
    border-radius: var(--border-radius-md);
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(52, 152, 219, 0.2);
}

.btn-accent:hover {
    background-color: var(--color-accent-light);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(52, 152, 219, 0.3);
}

.btn-accent svg {
    transition: transform 0.3s ease;
}

.btn-accent:hover svg {
    transform: translateX(4px);
}

@keyframes gradientFlow {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* 响应式调整 */
@media (max-width: 768px) {
    .hero-section {
        padding: var(--spacing-xl) var(--spacing-md);
    }
    
    .hero-content h1 {
        font-size: var(--font-size-2xl);
    }
    
    .tagline span {
        font-size: var(--font-size-md);
    }
    
    .btn-accent {
        padding: var(--spacing-sm) var(--spacing-lg);
        font-size: var(--font-size-md);
    }
}

/* 侧边导航 */
.sidebar-nav {
    position: fixed;
    left: 0;
    top: 0;
    height: 100%;
    width: 250px;
    background-color: white;
    box-shadow: var(--shadow-lg);
    transform: translateX(-100%);
    transition: transform var(--transition-normal) ease;
    z-index: 1000;
    overflow-y: auto;
}

.sidebar-nav.open {
    transform: translateX(0);
}

.sidebar-toggle {
    position: fixed;
    top: var(--spacing-md);
    left: var(--spacing-md);
    z-index: 1001;
    background-color: rgba(255, 255, 255, 0.8);
    border: none;
    border-radius: var(--border-radius-full);
    width: 2.5rem;
    height: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    transition: all var(--transition-fast) ease;
}

.sidebar-toggle:hover {
    background-color: white;
    transform: scale(1.05);
}

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

.sidebar-title {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
    color: var(--color-primary);
}

.sidebar-close {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-text-light);
    font-size: var(--font-size-xl);
    padding: 0;
    transition: color var(--transition-fast) ease;
}

/* 登录提示弹窗样式 */
.login-prompt-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 9999;
        display: flex;
        align-items: center;
        justify-content: center;
        opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.login-prompt-overlay.show {
    opacity: 1;
    visibility: visible;
}

.login-prompt-modal {
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    max-width: 400px;
    width: calc(100% - 40px);
    max-height: calc(100vh - 40px);
    overflow: hidden;
    transform: scale(0.8) translateY(20px);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.login-prompt-overlay.show .login-prompt-modal {
    transform: scale(1) translateY(0);
}

.login-prompt-header {
    padding: 24px 24px 16px;
    border-bottom: 1px solid #f1f5f9;
    text-align: center;
}

.login-prompt-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
}

.login-prompt-title {
    font-size: 20px;
    font-weight: 600;
    color: #1e293b;
    margin: 0 0 8px;
}

.login-prompt-subtitle {
    font-size: 14px;
    color: #64748b;
    margin: 0;
    line-height: 1.5;
}

.login-prompt-body {
    padding: 20px 24px;
}

.login-prompt-message {
    font-size: 15px;
    color: #475569;
    line-height: 1.6;
    margin: 0 0 24px;
    text-align: center;
}

.login-prompt-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
}

.login-prompt-btn {
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 100px;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.login-prompt-btn-primary {
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    color: white;
    box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3);
}

.login-prompt-btn-primary:hover {
    background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
    transform: translateY(-1px);
    color: white;
    text-decoration: none;
}

.login-prompt-btn-secondary {
    background: #f8fafc;
    color: #64748b;
    border: 1px solid #e2e8f0;
}

.login-prompt-btn-secondary:hover {
    background: #f1f5f9;
    color: #475569;
    border-color: #cbd5e1;
    transform: translateY(-1px);
}

.login-prompt-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 32px;
    height: 32px;
    border: none;
    background: #f8fafc;
    border-radius: 8px;
    color: #64748b;
    cursor: pointer;
    display: flex;
        align-items: center;
    justify-content: center;
    font-size: 18px;
    transition: all 0.2s ease;
}

.login-prompt-close:hover {
    background: #f1f5f9;
    color: #475569;
    transform: scale(1.05);
}

/* 平板设备优化 */
@media (min-width: 481px) and (max-width: 768px) {
    .login-prompt-modal {
        max-width: 360px;
    }
    
    .login-prompt-header {
        padding: 20px 20px 14px;
    }
    
    .login-prompt-icon {
        width: 44px;
        height: 44px;
        font-size: 22px;
        margin-bottom: 14px;
    }
    
    .login-prompt-title {
        font-size: 18px;
    }
    
    .login-prompt-body {
        padding: 18px 20px;
    }
    
    .login-prompt-btn {
        padding: 14px 20px;
        font-size: 15px;
        min-width: 110px;
    }
}

/* 移动设备优化 */
@media (max-width: 480px) {
    .login-prompt-modal {
        max-width: 320px;
        width: calc(100% - 20px);
        border-radius: 12px;
    }
    
    .login-prompt-header {
        padding: 18px 18px 12px;
    }
    
    .login-prompt-icon {
        width: 40px;
        height: 40px;
        font-size: 20px;
        margin-bottom: 12px;
    }
    
    .login-prompt-title {
        font-size: 17px;
    }
    
    .login-prompt-subtitle {
        font-size: 13px;
    }
    
    .login-prompt-body {
        padding: 16px 18px;
    }
    
    .login-prompt-message {
        font-size: 14px;
        margin-bottom: 20px;
    }
    
    .login-prompt-actions {
        flex-direction: column;
        gap: 10px;
    }
    
    .login-prompt-btn {
        padding: 14px 20px;
        font-size: 15px;
        width: 100%;
    }
    
    .login-prompt-close {
        top: 12px;
        right: 12px;
        width: 28px;
        height: 28px;
        font-size: 16px;
    }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
    .login-prompt-modal {
        border: 2px solid #000;
    }
    
    .login-prompt-btn-primary {
        background: #000;
        color: #fff;
        border: 2px solid #000;
    }
    
    .login-prompt-btn-secondary {
        background: #fff;
        color: #000;
        border: 2px solid #000;
    }
}

/* 减少动画模式支持 */
@media (prefers-reduced-motion: reduce) {
    .login-prompt-overlay,
    .login-prompt-modal,
    .login-prompt-btn,
    .login-prompt-close {
        transition: none;
    }
    
    .login-prompt-overlay.show .login-prompt-modal {
        transform: none;
    }
}