/*
 * Chrome 下载页面 - 现代简洁风格
 * 布局：简洁、清晰、易用
 */

/* ===== 变量 ===== */
:root {
    --primary: #4285f4;
    --primary-dark: #3367d6;
    --secondary: #34a853;
    --accent: #ea4335;
    --warning: #fbbc04;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #f1f3f4;
    
    --text-primary: #202124;
    --text-secondary: #5f6368;
    --text-light: #9aa0a6;
    
    --border-color: #dadce0;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    
    --transition: 0.3s ease;
}

/* ===== 基础样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text-primary);
    background: var(--bg-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    padding: 16px 0;
    transition: var(--transition);
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: conic-gradient(
        #ea4335 0deg 90deg,
        #fbbc04 90deg 180deg,
        #34a853 180deg 270deg,
        #4285f4 270deg 360deg
    );
    border-radius: 50%;
}

.brand-text {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition);
}

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

.nav-cta {
    background: var(--primary);
    color: white;
    padding: 10px 24px;
    border-radius: var(--radius-full);
    font-weight: 500;
    transition: var(--transition);
}

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

/* ===== 主视觉区 ===== */
.hero {
    padding: 120px 0 80px;
    position: relative;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    opacity: 0.03;
    z-index: -1;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.hero-text {
    max-width: 540px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.hero-desc {
    font-size: 1.25rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 32px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 1rem;
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary {
    background: var(--primary);
    color: white;
    border: none;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

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

.btn-large {
    padding: 16px 36px;
    font-size: 1.1rem;
}

.hero-visual {
    display: flex;
    justify-content: center;
}

.browser-window {
    width: 100%;
    max-width: 540px;
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.browser-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}

.browser-dots {
    display: flex;
    gap: 6px;
}

.browser-dots .dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #ddd;
}

.browser-dots .dot:nth-child(1) { background: #ff5f57; }
.browser-dots .dot:nth-child(2) { background: #febc2e; }
.browser-dots .dot:nth-child(3) { background: #28c840; }

.browser-url {
    flex: 1;
    height: 32px;
    background: white;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.browser-body {
    padding: 24px;
}

.content-blocks {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.content-blocks .block {
    height: 80px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

/* ===== 统计数据 ===== */
.stats {
    padding: 60px 0;
    background: var(--bg-secondary);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.stat-item {
    text-align: center;
    padding: 24px;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* ===== 特性区域 ===== */
.features {
    padding: 100px 0;
}

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

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.section-header p {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

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

.feature-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.feature-icon {
    width: 56px;
    height: 56px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    font-size: 1.5rem;
    color: var(--primary);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== 下载区域 ===== */
.download {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.download-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.download-info h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.download-info > p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.platform-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.platform-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.platform-item:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.platform-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary);
}

.platform-info {
    flex: 1;
}

.platform-info h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.platform-info span {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.download-btn {
    padding: 10px 24px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius-full);
    font-weight: 500;
    transition: var(--transition);
}

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

.version-note {
    text-align: center;
    padding: 16px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
}

.version-note span {
    color: var(--text-primary);
    font-weight: 600;
}

.download-visual {
    display: flex;
    justify-content: center;
}

.download-card {
    width: 100%;
    max-width: 400px;
    padding: 48px;
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    text-align: center;
    border: 1px solid var(--border-color);
}

.download-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: white;
}

.download-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.download-card > p {
    color: var(--text-secondary);
    margin-bottom: 32px;
}

/* ===== FAQ ===== */
.faq {
    padding: 100px 0;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    margin-bottom: 16px;
    overflow: hidden;
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px;
    background: white;
    cursor: pointer;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--bg-secondary);
}

.faq-question h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.faq-question i {
    color: var(--text-light);
    transition: var(--transition);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: var(--transition);
}

.faq-answer p {
    padding: 0 24px 24px;
    color: var(--text-secondary);
}

.faq-item.active .faq-answer {
    max-height: 200px;
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
    color: var(--primary);
}

/* ===== 页脚 ===== */
.footer {
    padding: 60px 0 24px;
    background: var(--bg-tertiary);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    gap: 64px;
    margin-bottom: 40px;
}

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

.footer-brand h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.footer-brand p {
    color: var(--text-secondary);
}

.footer-links {
    display: flex;
    gap: 64px;
}

.link-group h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.link-group a {
    display: block;
    color: var(--text-secondary);
    margin-bottom: 12px;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
    color: var(--text-light);
    font-size: 0.9rem;
}

/* ===== 下载页面特有样式 ===== */

/* 下载主视觉 */
.download-hero {
    padding: 140px 0 80px;
    background: var(--bg-secondary);
    text-align: center;
}

.download-hero .hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.download-hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.download-hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.version-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--primary);
    color: white;
    padding: 8px 20px;
    border-radius: var(--radius-full);
    font-weight: 500;
    font-size: 0.9rem;
}

/* 下载平台 */
.download-platforms {
    padding: 60px 0;
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.platform-card {
    padding: 40px 32px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    text-align: center;
    transition: var(--transition);
}

.platform-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.platform-card .platform-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: var(--primary);
}

.platform-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.platform-card > p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.platform-details {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 24px;
}

.file-size,
.file-type {
    font-size: 0.85rem;
    color: var(--text-secondary);
    padding: 4px 12px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
}

.platform-card .download-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius-full);
    font-weight: 500;
    transition: var(--transition);
}

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

/* 安装指南 */
.install-guide {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.guide-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 32px;
}

.step-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 20px;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
}

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

.step-content p {
    color: var(--text-secondary);
}

/* 系统要求 */
.system-reqs {
    padding: 80px 0;
}

.reqs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.req-card {
    padding: 32px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
}

.req-icon {
    width: 56px;
    height: 56px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 20px;
}

.req-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.req-card ul {
    list-style: none;
}

.req-card li {
    color: var(--text-secondary);
    padding: 8px 0;
    padding-left: 24px;
    position: relative;
}

.req-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: 600;
}

/* 版本信息 */
.version-info {
    padding: 60px 0;
    background: var(--bg-secondary);
}

.version-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 32px;
}

.version-left {
    display: flex;
    align-items: center;
    gap: 20px;
}

.version-icon {
    width: 60px;
    height: 60px;
    background: var(--primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
}

.version-details h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.version-details p {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 4px;
}

.version-date {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.version-features {
    display: flex;
    gap: 24px;
}

.version-feature {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
}

.version-feature i {
    color: var(--secondary);
}

/* ===== 404页面特有样式 ===== */

/* 404主视觉 */
.error-hero {
    padding: 140px 0 80px;
    background: var(--bg-secondary);
    text-align: center;
}

.error-hero .hero-content {
    max-width: 700px;
    margin: 0 auto;
}

.error-illustration {
    margin-bottom: 40px;
    position: relative;
    display: inline-block;
}

.error-number {
    font-size: 10rem;
    font-weight: 900;
    line-height: 1;
    color: var(--primary);
    opacity: 0.1;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    white-space: nowrap;
}

.error-icon {
    width: 150px;
    height: 150px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: white;
    margin: 0 auto;
    position: relative;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 0 0 0 rgba(66, 133, 244, 0.4);
    }
    50% {
        transform: scale(1.05);
        box-shadow: 0 0 0 20px rgba(66, 133, 244, 0);
    }
}

.error-hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.error-hero p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.7;
}

.error-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* 搜索帮助 */
.search-help {
    padding: 60px 0;
    background: white;
}

.search-help h2 {
    text-align: center;
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 32px;
    color: var(--text-primary);
}

.search-form {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    gap: 12px;
}

.search-input-wrapper {
    flex: 1;
    position: relative;
}

.search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.search-input-wrapper input {
    width: 100%;
    padding: 14px 16px 14px 48px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    transition: var(--transition);
}

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

.search-btn {
    padding: 14px 28px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius-lg);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

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

/* 快速链接 */
.quick-links {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.quick-links h2 {
    text-align: center;
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 40px;
    color: var(--text-primary);
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.link-card {
    background: white;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: 32px;
    text-decoration: none;
    transition: var(--transition);
    display: block;
}

.link-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.link-icon {
    width: 64px;
    height: 64px;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    color: var(--primary);
    margin-bottom: 20px;
}

.link-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.link-card p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.6;
    font-size: 0.95rem;
}

.link-arrow {
    color: var(--primary);
    font-weight: 600;
    font-size: 0.9rem;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.link-card:hover .link-arrow i {
    transform: translateX(4px);
    transition: var(--transition);
}

/* 帮助中心 */
.help-center {
    padding: 80px 0;
    background: white;
}

.help-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
}

.help-left h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.help-left p {
    color: var(--text-secondary);
    margin-bottom: 24px;
    line-height: 1.7;
}

.help-list {
    list-style: none;
}

.help-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 0;
    color: var(--text-secondary);
}

.help-list li i {
    color: var(--primary);
    font-size: 1.25rem;
}

.contact-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: 48px;
    text-align: center;
}

.contact-icon {
    width: 80px;
    height: 80px;
    background: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
    margin: 0 auto 24px;
}

.contact-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.contact-card p {
    color: var(--text-secondary);
    margin-bottom: 24px;
    line-height: 1.6;
}

/* ===== 辅助类 ===== */
.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--primary);
    color: white;
    padding: 8px 16px;
    z-index: 1001;
    font-weight: 600;
    transition: var(--transition);
}

.skip-link:focus {
    top: 16px;
}

/* ===== 响应式 ===== */
@media (max-width: 992px) {
    .hero-content,
    .download-content {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .hero-visual {
        order: -1;
    }

    .features-grid,
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-content {
        flex-direction: column;
    }

    .help-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        gap: 12px;
        border-top: 1px solid var(--border-color);
        box-shadow: var(--shadow-lg);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-10px);
        transition: all var(--transition);
    }

    .nav-menu.active {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

    .nav-menu .nav-btn {
        width: 100%;
        justify-content: center;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .features-grid,
    .stats-grid {
        grid-template-columns: 1fr;
    }

    .footer-links {
        flex-direction: column;
        gap: 32px;
    }

    .hero-buttons {
        flex-direction: column;
    }

    /* 404页面响应式 */
    .error-hero {
        padding: 100px 0 60px;
    }

    .error-number {
        font-size: 7rem;
    }

    .error-icon {
        width: 120px;
        height: 120px;
        font-size: 3rem;
    }

    .error-hero h1 {
        font-size: 2rem;
    }

    .error-actions {
        flex-direction: column;
        align-items: center;
    }

    .error-actions .btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }

    .search-form {
        flex-direction: column;
    }

    .links-grid {
        grid-template-columns: 1fr;
    }

    .help-content {
        grid-template-columns: 1fr;
    }

    .contact-card {
        padding: 32px;
    }
}

@media (max-width: 576px) {
    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 2rem;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .platform-item {
        flex-direction: column;
        text-align: center;
    }

    /* 404页面移动端 */
    .error-hero {
        padding: 80px 0 40px;
    }

    .error-number {
        font-size: 5rem;
    }

    .error-icon {
        width: 100px;
        height: 100px;
        font-size: 2.5rem;
    }

    .error-hero h1 {
        font-size: 1.75rem;
    }

    .error-hero p {
        font-size: 1rem;
    }
}