/* 基础样式和重置 */
:root {
    --primary-color: #007AFF;
    --primary-dark: #0056CC;
    --secondary-color: #6C757D;
    --success-color: #28A745;
    --danger-color: #DC3545;
    --warning-color: #FFC107;
    --light-color: #F8F9FA;
    --dark-color: #212529;
    --gray-color: #6C757D;
    --border-color: #DEE2E6;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: #fff;
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 无障碍功能 */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px;
    text-decoration: none;
    z-index: 1000;
}

.skip-link:focus {
    top: 0;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    gap: 8px;
}

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

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

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

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

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

.btn-large {
    padding: 16px 32px;
    font-size: 18px;
}

.btn-block {
    width: 100%;
}

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

.btn-download:hover {
    background-color: #218838;
}

/* 导航栏 */
.site-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 16px 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.logo i {
    font-size: 28px;
}

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

.nav-link {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--dark-color);
    text-decoration: none;
    font-weight: 500;
    padding: 8px 0;
    position: relative;
    transition: var(--transition);
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px 0;
    background-color: var(--dark-color);
    transition: var(--transition);
}

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

/* 英雄区域 */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('images/hero-pattern.svg') center/cover;
    opacity: 0.1;
}

.hero .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
    position: relative;
    z-index: 1;
}

.hero-content {
    flex: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
}

.hero-title .highlight {
    color: #FFD700;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 32px;
    opacity: 0.9;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-stats {
    display: flex;
    gap: 32px;
}

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

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.8;
}

.hero-image {
    flex: 1;
    text-align: center;
}

.hero-image img {
    max-width: 100%;
    height: auto;
    filter: drop-shadow(0 20px 40px rgba(0, 0, 0, 0.3));
}

/* 区域标题 */
.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--dark-color);
}

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

/* 功能卡片 */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: white;
    border-radius: 12px;
    padding: 32px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    background: linear-gradient(135deg, var(--primary-color), #764ba2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feature-icon i {
    font-size: 32px;
    color: white;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    color: var(--dark-color);
}

.feature-card p {
    color: var(--gray-color);
    line-height: 1.6;
}

/* 价格卡片 */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.pricing-card {
    background: white;
    border-radius: 12px;
    padding: 32px;
    box-shadow: var(--shadow);
    border: 2px solid var(--border-color);
    position: relative;
    transition: var(--transition);
}

.pricing-card.featured {
    border-color: var(--primary-color);
    transform: scale(1.05);
}

.pricing-card:hover {
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 6px 20px;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.pricing-header {
    text-align: center;
    margin-bottom: 24px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
}

.pricing-header h3 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    color: var(--dark-color);
}

.price {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 4px;
}

.price .currency {
    font-size: 1.5rem;
    color: var(--gray-color);
}

.price .amount {
    font-size: 3rem;
    font-weight: 700;
    color: var(--dark-color);
}

.price .period {
    font-size: 1rem;
    color: var(--gray-color);
}

.pricing-features {
    list-style: none;
    margin-bottom: 32px;
}

.pricing-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
    color: var(--gray-color);
}

.pricing-features i {
    color: var(--success-color);
}

/* 平台卡片 */
.platforms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.platform-card {
    background: white;
    border-radius: 12px;
    padding: 32px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.platform-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.platform-icon {
    margin-bottom: 24px;
}

.platform-icon i {
    font-size: 48px;
    color: var(--primary-color);
}

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

.platform-card p {
    color: var(--gray-color);
    margin-bottom: 24px;
}

/* 用户评价 */
.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.testimonial-card {
    background: white;
    border-radius: 12px;
    padding: 32px;
    box-shadow: var(--shadow);
}

.testimonial-content {
    margin-bottom: 24px;
    font-style: italic;
    color: var(--gray-color);
    line-height: 1.8;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 16px;
}

.author-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    overflow: hidden;
    background: var(--light-color);
}

.author-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.author-info h4 {
    font-size: 1rem;
    margin-bottom: 4px;
    color: var(--dark-color);
}

.author-info p {
    font-size: 0.875rem;
    color: var(--gray-color);
}

/* 常见问题 */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    margin-bottom: 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
}

.faq-question {
    padding: 20px 24px;
    background: var(--light-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 500;
    color: var(--dark-color);
    list-style: none;
}

.faq-question::-webkit-details-marker {
    display: none;
}

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

.faq-item[open] .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    padding: 24px;
    background: white;
    line-height: 1.6;
}

/* CTA区域 */
.cta {
    background: linear-gradient(135deg, var(--primary-color), #764ba2);
    color: white;
    padding: 80px 0;
    text-align: center;
}

.cta-content h2 {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.cta-content p {
    font-size: 1.25rem;
    margin-bottom: 32px;
    opacity: 0.9;
}

/* 页脚 */
.site-footer {
    background: var(--dark-color);
    color: white;
    padding: 80px 0 32px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 48px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 24px;
    font-weight: 700;
    color: white;
    text-decoration: none;
    margin-bottom: 16px;
}

.footer-description {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 24px;
    line-height: 1.6;
}

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

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: white;
    text-decoration: none;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-col h3 {
    font-size: 1.25rem;
    margin-bottom: 24px;
    color: white;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: white;
    padding-left: 4px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 32px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.copyright {
    color: rgba(255, 255, 255, 0.7);
}

.footer-lang select {
    background: transparent;
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    padding: 8px 16px;
    border-radius: 4px;
    cursor: pointer;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
}

/* 下载页面特定样式 */
.download-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
}

.download-intro h1 {
    font-size: 3rem;
    margin-bottom: 16px;
}

.download-subtitle {
    font-size: 1.25rem;
    margin-bottom: 32px;
    opacity: 0.9;
}

.download-stats {
    display: flex;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
}

.download-stats .stat {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.1);
    padding: 12px 24px;
    border-radius: 50px;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.download-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    border: 2px solid var(--border-color);
    transition: var(--transition);
}

.download-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.download-card.highlighted {
    border-color: var(--primary-color);
    animation: highlight 2s ease;
}

@keyframes highlight {
    0%, 100% { border-color: var(--border-color); }
    50% { border-color: var(--primary-color); }
}

.download-card-header {
    padding: 32px 32px 24px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
    background: var(--light-color);
}

.platform-info h3 {
    font-size: 1.75rem;
    margin: 16px 0 8px;
    color: var(--dark-color);
}

.platform-version {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 4px;
}

.file-size {
    color: var(--gray-color);
    font-size: 0.875rem;
}

.download-card-body {
    padding: 24px 32px 32px;
}

.feature-list {
    list-style: none;
    margin-bottom: 24px;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
    color: var(--gray-color);
}

.feature-list i {
    color: var(--success-color);
}

.download-actions {
    text-align: center;
}

.download-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 16px;
}

.additional-links {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.additional-links .link {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.875rem;
    transition: var(--transition);
}

.additional-links .link:hover {
    text-decoration: underline;
}

/* 安装指南 */
.guide-tabs {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.tab-buttons {
    display: flex;
    background: var(--light-color);
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    flex: 1;
    padding: 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    color: var(--gray-color);
    transition: var(--transition);
    position: relative;
}

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

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--primary-color);
}

.tab-content {
    padding: 40px;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.guide-steps {
    list-style: none;
    counter-reset: step-counter;
}

.guide-steps li {
    position: relative;
    padding-left: 60px;
    margin-bottom: 40px;
    counter-increment: step-counter;
}

.guide-steps li::before {
    content: counter(step-counter);
    position: absolute;
    left: 0;
    top: 0;
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.25rem;
}

.guide-steps h4 {
    font-size: 1.25rem;
    margin-bottom: 8px;
    color: var(--dark-color);
}

.guide-steps p {
    color: var(--gray-color);
    line-height: 1.6;
}

.note {
    background: #FFF3CD;
    border: 1px solid #FFEEBA;
    color: #856404;
    padding: 12px;
    border-radius: 6px;
    margin-top: 8px;
    font-size: 0.875rem;
}

/* 系统要求 */
.requirements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.requirement-card {
    background: white;
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--shadow);
}

.requirement-card h3 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    color: var(--dark-color);
    text-align: center;
}

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

.requirement-card li {
    margin-bottom: 12px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
    color: var(--gray-color);
}

.requirement-card li:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.requirement-card li strong {
    color: var(--dark-color);
}

/* 下载完成区域 */
.download-complete {
    text-align: center;
    padding: 80px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.success-icon {
    color: #28A745;
    margin-bottom: 24px;
}

.complete-content h2 {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.complete-content p {
    font-size: 1.25rem;
    margin-bottom: 32px;
    opacity: 0.9;
}

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

/* 响应式设计 */
@media (max-width: 992px) {
    .hero .container {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-image {
        max-width: 500px;
        margin: 0 auto;
    }
}

@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }
    
    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
        z-index: 999;
    }
    
    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .pricing-card.featured {
        transform: none;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
    
    .tab-buttons {
        flex-direction: column;
    }
    
    .tab-btn {
        border-bottom: 1px solid var(--border-color);
    }
    
    .tab-btn.active::after {
        height: 100%;
        width: 3px;
        left: 0;
        top: 0;
    }
}

@media (max-width: 576px) {
    .hero-actions,
    .complete-actions {
        flex-direction: column;
    }
    
    .btn-large {
        width: 100%;
    }
    
    .download-stats {
        flex-direction: column;
        align-items: center;
        gap: 16px;
    }
    
    .guide-steps li {
        padding-left: 50px;
    }
    
    .guide-steps li::before {
        width: 30px;
        height: 30px;
        font-size: 1rem;
    }
}

/* 暗色模式 */
@media (prefers-color-scheme: dark) {
    body {
        background-color: #121212;
        color: #E0E0E0;
    }
    
    .feature-card,
    .pricing-card,
    .platform-card,
    .testimonial-card,
    .download-card,
    .guide-tabs,
    .requirement-card {
        background-color: #1E1E1E;
        color: #E0E0E0;
    }
    
    .site-header {
        background-color: rgba(30, 30, 30, 0.95);
    }
    
    .nav-link {
        color: #E0E0E0;
    }
    
    .faq-question {
        background-color: #2D2D2D;
        color: #E0E0E0;
    }
    
    .faq-answer {
        background-color: #1E1E1E;
        color: #B0B0B0;
    }
}