/* 基础样式重置 */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 性能优化：减少重排重绘 */
html {
    font-size: 16px;
    line-height: 1.6;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
        'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
        sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    color: #333;
    background-color: #f5f5f5;
    overflow-x: hidden;
}

/* 提升文本渲染性能 */
body {
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* 头部导航样式 */
.header {
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo svg {
    width: 48px;
    height: 48px;
    flex-shrink: 0;
}

.logo h1 {
    font-size: 24px;
    font-weight: 700;
    color: #4285f4;
    margin: 0;
}

/* 移动端LOGO样式 */
@media (max-width: 480px) {
    .logo svg {
        width: 36px;
        height: 36px;
    }
    
    .logo h1 {
        font-size: 20px;
    }
}

.nav ul {
    display: flex;
    list-style: none;
}

.nav ul li {
    margin-left: 30px;
}

.nav ul li a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav ul li a:hover {
    color: #4285f4;
}

/* 英雄区域样式 */
.hero {
    background: linear-gradient(135deg, #4285f4, #34a853);
    color: #fff;
    padding: 150px 0 100px;
    text-align: center;
    margin-top: 80px;
}

.hero-content h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-content p {
    font-size: 18px;
    margin-bottom: 40px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
}

.btn-primary {
    background-color: #fff;
    color: #4285f4;
    padding: 15px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn-primary:hover {
    background-color: #f8f9fa;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background-color: transparent;
    color: #fff;
    padding: 15px 30px;
    border: 2px solid #fff;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

/* 功能介绍样式 */
.features {
    padding: 100px 0;
    background-color: #fff;
}

.features h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 60px;
    color: #202124;
}

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

.feature-card {
    background-color: #f8f9fa;
    padding: 40px;
    border-radius: 10px;
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background-color: #4285f4;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 24px;
    transition: all 0.3s ease;
}

.feature-card:hover .feature-icon {
    background-color: #34a853;
    transform: scale(1.1);
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 15px;
    color: #202124;
}

.feature-card p {
    color: #5f6368;
    line-height: 1.6;
}

/* 安全性介绍样式 */
.security {
    padding: 100px 0;
    background-color: #f8f9fa;
}

.security h2 {
    text-align: center;
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 60px;
    color: #202124;
}

.security-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.security-item {
    background-color: #fff;
    padding: 40px;
    border-radius: 10px;
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.security-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.security-item h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 15px;
    color: #202124;
}

.security-item p {
    color: #5f6368;
    line-height: 1.6;
}

/* 下载页面英雄区域 */
.download-hero {
    background: linear-gradient(135deg, #4285f4, #34a853);
    color: #fff;
    padding: 150px 0 50px;
    text-align: center;
    margin-top: 80px;
}

.download-hero-content h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.download-hero-content p {
    font-size: 18px;
    margin-bottom: 40px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* 下载选项样式 */
.download-options {
    padding: 80px 0;
    background-color: #fff;
}

.download-card {
    background-color: #f8f9fa;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 30px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.download-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.download-card-header {
    background-color: #4285f4;
    color: #fff;
    padding: 30px;
}

.download-card-header h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 10px;
}

.download-card-header p {
    font-size: 16px;
    opacity: 0.9;
}

.download-card-content {
    padding: 30px;
}

.download-buttons {
    margin-bottom: 30px;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background-color: #4285f4;
    color: #fff;
    padding: 20px 40px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 18px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(66, 133, 244, 0.3);
}

.btn-download:hover {
    background-color: #3367d6;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(66, 133, 244, 0.4);
}

.download-info {
    color: #5f6368;
    font-size: 14px;
}

/* 下载详情样式 */
.download-details {
    padding: 80px 0;
    background-color: #f8f9fa;
}

.download-section {
    background-color: #fff;
    padding: 30px;
    border-radius: 10px;
    margin-bottom: 30px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.download-section h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #202124;
    border-bottom: 2px solid #4285f4;
    padding-bottom: 10px;
}

.download-section ul {
    list-style: none;
}

.download-section ul li {
    margin-bottom: 10px;
    color: #5f6368;
    padding-left: 25px;
    position: relative;
}

.download-section ul li:before {
    content: "•";
    color: #4285f4;
    font-size: 20px;
    position: absolute;
    left: 0;
    top: -2px;
}

/* 系统要求样式 */
.system-requirements {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.requirement-item h4 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 15px;
    color: #202124;
}

/* 常见问题样式 */
.faq-item {
    margin-bottom: 20px;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: 5px;
}

.faq-item h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 10px;
    color: #202124;
}

.faq-item p {
    color: #5f6368;
    line-height: 1.6;
    margin-bottom: 0;
}

/* 底部信息样式 */
.footer {
    background-color: #202124;
    color: #fff;
    padding: 80px 0 40px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #4285f4;
}

.footer-section h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #4285f4;
}

.footer-section p {
    color: #bdc1c6;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 10px;
    color: #bdc1c6;
}

.footer-section ul li a {
    color: #bdc1c6;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #4285f4;
}

.footer-bottom {
    text-align: center;
    padding-top: 40px;
    border-top: 1px solid #303134;
    color: #9aa0a6;
    font-size: 14px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 20px;
        padding: 20px 0;
    }

    .nav ul {
        gap: 20px;
    }

    .hero-content h2 {
        font-size: 36px;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .features h2 {
        font-size: 28px;
    }

    .security h2 {
        font-size: 28px;
    }

    .download-hero-content h2 {
        font-size: 36px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .system-requirements {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-content h2 {
        font-size: 28px;
    }

    .hero-content p {
        font-size: 16px;
    }

    .feature-card {
        padding: 30px;
    }

    .btn-primary,
    .btn-secondary,
    .btn-download {
        padding: 12px 24px;
        font-size: 14px;
    }

    .download-card-header {
        padding: 20px;
    }

    .download-card-content {
        padding: 20px;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card {
    animation: fadeInUp 0.6s ease-out;
}

.feature-card:nth-child(2) {
    animation-delay: 0.2s;
}

.feature-card:nth-child(3) {
    animation-delay: 0.4s;
}

.feature-card:nth-child(4) {
    animation-delay: 0.6s;
}

.feature-card:nth-child(5) {
    animation-delay: 0.8s;
}

.feature-card:nth-child(6) {
    animation-delay: 1s;
}

.security-item {
    animation: fadeInUp 0.6s ease-out;
}

.security-item:nth-child(2) {
    animation-delay: 0.2s;
}

.security-item:nth-child(3) {
    animation-delay: 0.4s;
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

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

::-webkit-scrollbar-thumb {
    background: #4285f4;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #3367d6;
}

/* 响应式导航样式 */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: #4285f4;
    font-size: 24px;
    cursor: pointer;
    padding: 10px;
    border-radius: 5px;
    transition: all 0.3s ease;
}

.menu-toggle:hover {
    background-color: rgba(66, 133, 244, 0.1);
}

.menu-toggle.active {
    color: #3367d6;
}

.header.scrolled {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

/* 移动端导航样式 */
@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }

    .nav {
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        background-color: #fff;
        box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
        padding: 20px 0;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
        z-index: 999;
    }

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

    .nav ul {
        flex-direction: column;
        align-items: center;
        gap: 20px;
    }

    .nav ul li {
        margin-left: 0;
    }
}

/* 下载通知样式 */
.download-notification {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: #4285f4;
    color: #fff;
    padding: 15px 20px;
    border-radius: 5px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transform: translateX(100%);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.download-notification.show {
    transform: translateX(0);
    opacity: 1;
}

.download-notification.success {
    background-color: #34a853;
}

/* 下载进度样式 */
.download-progress {
    position: fixed;
    bottom: 20px;
    left: 20px;
    right: 20px;
    background-color: #fff;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transform: translateY(100%);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.download-progress.show {
    transform: translateY(0);
    opacity: 1;
}

.progress-bar {
    width: 100%;
    height: 10px;
    background-color: #f1f1f1;
    border-radius: 5px;
    overflow: hidden;
    margin-bottom: 15px;
}

.progress-fill {
    width: 0%;
    height: 100%;
    background-color: #4285f4;
    transition: width 0.3s ease;
    border-radius: 5px;
}

.download-progress p {
    margin: 0;
    color: #202124;
    font-weight: 500;
    text-align: center;
}