/* ========================================
   Pdftoword 官网 - 现代简洁风格样式表
   ======================================== */

/* CSS 变量定义 - 支持亮色/暗色主题 */
:root {
    /* 亮色主题 */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --border-color: #e2e8f0;
    
    /* 主色调 */
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #dbeafe;
    
    /* 辅助色 */
    --success: #10b981;
    --success-light: #d1fae5;
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* 圆角 */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* 暗色主题 */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --border-color: #334155;
    
    --primary-light: #1e3a5f;
    --success-light: #064e3b;
    --warning-light: #78350f;
}

/* ========================================
   基础重置与排版
   ======================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color var(--transition-normal), color var(--transition-normal);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

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

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul, ol {
    list-style: none;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    font-family: inherit;
}

/* ========================================
   布局容器
   ======================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 2.25rem;
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 70px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

[data-theme="dark"] .navbar.scrolled {
    background: rgba(15, 23, 42, 0.9);
}

.navbar-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-icon {
    width: 36px;
    height: 36px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 40px;
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: 1px;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

/* 主题切换按钮 */
.theme-toggle {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    background: var(--primary);
    color: white;
    transform: rotate(15deg);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    width: 44px;
    height: 44px;
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    align-items: center;
    justify-content: center;
}

.mobile-menu-btn svg {
    width: 24px;
    height: 24px;
}

/* ========================================
   按钮样式
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    white-space: nowrap;
}

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

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

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--border-color);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

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

.btn-lg {
    padding: 16px 32px;
    font-size: 1.05rem;
}

.btn-icon {
    width: 20px;
    height: 20px;
}

/* ========================================
   Hero 区域
   ======================================== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    overflow: hidden;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-text {
    animation: fadeInUp 0.8s ease;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--primary-light);
    color: var(--primary);
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 50px;
    margin-bottom: 24px;
}

.hero-title {
    font-size: 3.25rem;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

.hero-title span {
    color: var(--primary);
}

.hero-description {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 40px;
}

.hero-stats {
    display: flex;
    gap: 40px;
}

.hero-stat {
    text-align: left;
}

.hero-stat-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

.hero-stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.hero-visual {
    position: relative;
    animation: fadeInRight 0.8s ease;
}

.hero-image {
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    overflow: hidden;
    background: var(--bg-primary);
}

.hero-image img {
    width: 100%;
    display: block;
}

.hero-floating {
    position: absolute;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    box-shadow: var(--shadow-lg);
    animation: float 3s ease-in-out infinite;
}

.hero-floating-1 {
    top: 20%;
    left: -30px;
    animation-delay: 0s;
}

.hero-floating-2 {
    bottom: 20%;
    right: -30px;
    animation-delay: 1.5s;
}

.floating-icon {
    width: 24px;
    height: 24px;
    color: var(--success);
}

.floating-text {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* ========================================
   特性卡片网格
   ======================================== */
.features {
    background: var(--bg-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.feature-icon svg {
    width: 28px;
    height: 28px;
}

.feature-icon.blue {
    background: var(--primary-light);
    color: var(--primary);
}

.feature-icon.green {
    background: var(--success-light);
    color: var(--success);
}

.feature-icon.yellow {
    background: var(--warning-light);
    color: var(--warning);
}

.feature-icon.purple {
    background: #ede9fe;
    color: #7c3aed;
}

[data-theme="dark"] .feature-icon.purple {
    background: #2e1065;
}

.feature-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.feature-description {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ========================================
   功能展示区
   ======================================== */
.showcase {
    background: var(--bg-secondary);
}

.showcase-item {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    margin-bottom: 80px;
}

.showcase-item:last-child {
    margin-bottom: 0;
}

.showcase-item.reverse {
    direction: rtl;
}

.showcase-item.reverse > * {
    direction: ltr;
}

.showcase-content {
    padding: 20px;
}

.showcase-label {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--primary);
    margin-bottom: 12px;
}

.showcase-title {
    font-size: 2rem;
    margin-bottom: 16px;
}

.showcase-description {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 24px;
}

.showcase-features {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.showcase-feature {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-secondary);
}

.showcase-feature svg {
    width: 20px;
    height: 20px;
    color: var(--success);
    flex-shrink: 0;
}

.showcase-visual {
    position: relative;
}

.showcase-image {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    overflow: hidden;
    background: var(--bg-primary);
}

/* ========================================
   语言支持展示
   ======================================== */
.languages {
    background: var(--bg-primary);
    text-align: center;
}

.languages-grid {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 24px;
    margin-top: 40px;
}

.language-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 16px 24px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.language-item:hover {
    border-color: var(--primary);
    transform: translateY(-4px);
}

.language-icon {
    font-size: 1.5rem;
}

.language-name {
    font-weight: 600;
    color: var(--text-primary);
}

/* ========================================
   CTA 区域
   ======================================== */
.cta-section {
    background: linear-gradient(135deg, var(--primary) 0%, #7c3aed 100%);
    text-align: center;
    color: white;
}

.cta-title {
    font-size: 2.5rem;
    color: white;
    margin-bottom: 16px;
}

.cta-description {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 32px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
}

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

.cta-btn:hover {
    background: #f8fafc;
    transform: translateY(-2px);
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand {
    max-width: 300px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.footer-description {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.footer-title {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-primary);
    margin-bottom: 20px;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-link {
    font-size: 0.95rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer-link:hover {
    color: var(--primary);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.footer-copyright {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.footer-social {
    display: flex;
    gap: 16px;
}

.social-link {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
}

.social-link svg {
    width: 20px;
    height: 20px;
}

/* ========================================
   下载页面样式
   ======================================== */
.page-hero {
    padding: 140px 0 60px;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    text-align: center;
}

.page-title {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.page-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 40px;
}

.download-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 40px;
}

.download-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    transition: all var(--transition-normal);
}

.download-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
}

.download-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    color: var(--primary);
}

.download-platform {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.download-version {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.download-features {
    text-align: left;
    margin-bottom: 24px;
}

.download-feature {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.download-feature svg {
    width: 16px;
    height: 16px;
    color: var(--success);
}

/* 网盘下载按钮样式 */
.download-options {
    margin-top: 40px;
}

.platform-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    max-width: 800px;
    margin: 0 auto;
}

.platform-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    transition: all var(--transition-normal);
}

.platform-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.platform-icon {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.platform-icon svg {
    width: 36px;
    height: 36px;
}

.platform-icon.baidu-icon {
    background: #e8f0fe;
    color: #4D4D4D;
}

[data-theme="dark"] .platform-icon.baidu-icon {
    background: #2d2d2d;
    color: #8c8c8c;
}

.platform-icon.quark-icon {
    background: #f5f0ff;
    color: #7c3aed;
}

[data-theme="dark"] .platform-icon.quark-icon {
    background: #2e1065;
    color: #a78bfa;
}

.platform-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.platform-card > p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 24px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    width: 100%;
}

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

.baidu-btn {
    background: #4D4D4D;
    color: white;
}

.baidu-btn:hover {
    background: #333333;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    color: white;
}

.quark-btn {
    background: linear-gradient(135deg, #7c3aed 0%, #a855f7 100%);
    color: white;
}

.quark-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    color: white;
}

/* 系统要求 */
.system-requirements {
    background: var(--bg-secondary);
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.requirement-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
}

.requirement-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.requirement-title svg {
    width: 24px;
    height: 24px;
    color: var(--primary);
}

.requirement-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.requirement-item {
    font-size: 0.95rem;
    color: var(--text-secondary);
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.requirement-item::before {
    content: '•';
    color: var(--primary);
    font-weight: bold;
}

/* ========================================
   文档页面样式
   ======================================== */
.docs-layout {
    display: grid;
    grid-template-columns: 260px 1fr;
    gap: 40px;
    padding: 140px 0 80px;
}

.docs-sidebar {
    position: sticky;
    top: 100px;
    height: fit-content;
}

.docs-nav {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
}

.docs-nav-title {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 16px;
    padding: 0 12px;
}

.docs-nav-link {
    display: block;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    margin-bottom: 4px;
}

.docs-nav-link:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.docs-nav-link.active {
    background: var(--primary-light);
    color: var(--primary);
    font-weight: 500;
}

.docs-content {
    min-width: 0;
}

.docs-section {
    margin-bottom: 60px;
    padding-bottom: 60px;
    border-bottom: 1px solid var(--border-color);
}

.docs-section:last-child {
    border-bottom: none;
}

.docs-section-title {
    font-size: 1.75rem;
    margin-bottom: 20px;
}

.docs-section p {
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 16px;
}

.docs-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin: 20px 0;
}

.docs-list li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    color: var(--text-secondary);
}

.docs-list li svg {
    width: 20px;
    height: 20px;
    color: var(--success);
    flex-shrink: 0;
    margin-top: 2px;
}

.docs-code {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    font-size: 0.9rem;
    overflow-x: auto;
    margin: 20px 0;
}

.docs-code code {
    color: var(--text-primary);
}

.docs-tip {
    background: var(--primary-light);
    border-left: 4px solid var(--primary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    padding: 16px 20px;
    margin: 20px 0;
}

.docs-tip-title {
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 8px;
}

.docs-tip p {
    margin: 0;
    font-size: 0.95rem;
}

/* ========================================
   关于页面样式
   ======================================== */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    padding: 140px 0 80px;
}

.about-text h2 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.about-text p {
    font-size: 1.05rem;
    line-height: 1.8;
    margin-bottom: 20px;
}

.about-values {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-top: 40px;
}

.value-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
}

.value-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: var(--primary-light);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
}

.value-icon svg {
    width: 24px;
    height: 24px;
}

.value-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.value-description {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.about-visual {
    position: relative;
}

.about-image {
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    overflow: hidden;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 60px;
}

.about-placeholder {
    text-align: center;
    color: var(--text-muted);
}

.about-placeholder svg {
    width: 120px;
    height: 120px;
    margin-bottom: 20px;
    opacity: 0.5;
}

/* ========================================
   动画关键帧
   ======================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

/* ========================================
   移动端响应式设计
   ======================================== */
@media (max-width: 1024px) {
    .hero-content,
    .showcase-item {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .showcase-item.reverse {
        direction: ltr;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .download-cards {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin-left: auto;
        margin-right: auto;
    }
    
    .platform-cards {
        grid-template-columns: 1fr;
        max-width: 400px;
    }
    
    .docs-layout {
        grid-template-columns: 1fr;
    }
    
    .docs-sidebar {
        position: static;
    }
    
    .docs-nav {
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero {
        padding: 120px 0 60px;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-floating {
        display: none;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-brand {
        max-width: 100%;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
    
    .cta-title {
        font-size: 2rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .requirements-grid {
        grid-template-columns: 1fr;
    }
    
    .about-values {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   移动端菜单覆盖层
   ======================================== */
.mobile-menu-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.mobile-menu-overlay.active {
    display: block;
    opacity: 1;
}

.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 320px;
    height: 100%;
    background: var(--bg-primary);
    z-index: 1001;
    padding: 80px 30px 30px;
    transition: right var(--transition-normal);
    overflow-y: auto;
}

.mobile-menu.active {
    right: 0;
}

.mobile-nav-links {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 40px;
}

.mobile-nav-link {
    display: block;
    padding: 16px 20px;
    border-radius: var(--radius-md);
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
    background: var(--bg-secondary);
    color: var(--primary);
}

.mobile-nav-actions {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.mobile-nav-actions .btn {
    width: 100%;
}

/* ========================================
   徽章样式
   ======================================== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 12px;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 50px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge-primary {
    background: var(--primary-light);
    color: var(--primary);
}

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

.badge-warning {
    background: var(--warning-light);
    color: var(--warning);
}

/* ========================================
   表格样式
   ======================================== */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

th, td {
    padding: 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--text-primary);
}

td {
    color: var(--text-secondary);
}

tr:last-child td {
    border-bottom: none;
}

tr:hover td {
    background: var(--bg-secondary);
}

/* ========================================
   返回顶部按钮
   ======================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-normal);
    z-index: 998;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.back-to-top svg {
    width: 24px;
    height: 24px;
}