/* SEO优化样式表 - 针对性能和搜索引擎优化的CSS */
:root {
    --primary-color: #FF9900;
    --secondary-color: #146EB4;
    --dark-color: #232F3E;
    --light-color: #F8F8F8;
    --success-color: #27AE60;
    --danger-color: #E74C3C;
    --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --transition-speed: 0.3s;
    --container-width: 1200px;
}

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

html {
    scroll-behavior: smooth; /* 原生平滑滚动 */
    font-size: 16px; /* 基础字体大小，便于使用rem单位 */
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
    overflow-x: hidden; /* 防止水平滚动条 */
    text-rendering: optimizeLegibility; /* 优化文本渲染 */
    -webkit-font-smoothing: antialiased; /* 字体平滑 */
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: var(--container-width);
    width: 90%; /* 流体宽度 */
    margin: 0 auto;
    padding: 0 15px;
}

/* 可访问性和SEO优化的标题样式 */
h1, h2, h3, h4 {
    margin-bottom: 15px;
    line-height: 1.3;
    color: var(--dark-color);
    font-weight: 700;
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: 1rem;
}

/* 链接样式优化 */
a {
    text-decoration: none;
    color: var(--dark-color);
    transition: color var(--transition-speed) ease;
    position: relative; /* 为悬停效果做准备 */
}

a:hover, a:focus {
    color: var(--primary-color);
    outline: none; /* 移除默认的焦点轮廓 */
}

a:focus {
    text-decoration: underline; /* 增强键盘导航的可访问性 */
}

/* 辅助类 - 可见性和焦点 */
.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;
}

/* 列表样式 */
ul {
    list-style: none;
}

/* 通用标题样式 */
.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: var(--dark-color);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 50px;
    height: 3px;
    background-color: var(--primary-color);
    margin: 15px auto 0;
}

/* 按钮样式优化 */
.btn-primary, .btn-secondary {
    display: inline-block;
    padding: 12px 25px;
    border-radius: 5px;
    font-weight: 700;
    transition: all var(--transition-speed) ease;
    cursor: pointer;
    text-align: center;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
    box-shadow: 0 4px 6px rgba(255, 153, 0, 0.2);
}

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

.btn-primary:hover, .btn-primary:focus {
    background-color: #E68A00;
    transform: translateY(-3px);
    box-shadow: 0 6px 12px rgba(255, 153, 0, 0.3);
}

.btn-secondary:hover, .btn-secondary:focus {
    background-color: var(--dark-color);
    color: #fff;
    transform: translateY(-3px);
}

.btn-large {
    padding: 15px 30px;
    font-size: 1.2rem;
}

/* 键盘用户焦点样式 */
button:focus, .btn-primary:focus, .btn-secondary:focus {
    outline: 3px solid rgba(255, 153, 0, 0.5);
    outline-offset: 2px;
}

/* 导航栏优化 */
header {
    background-color: #fff;
    box-shadow: var(--box-shadow);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    transition: all 0.4s ease;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
    transition: padding 0.3s ease;
}

/* 优化logo的文本大小和SEO */
.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
    transition: all var(--transition-speed) ease;
}

.logo a {
    color: var(--primary-color);
    text-decoration: none;
}

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

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

.nav-links a {
    font-weight: 500;
    transition: color var(--transition-speed) ease;
    position: relative;
    padding: 5px 0;
}

/* 添加普通导航链接悬停效果 */
.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--primary-color);
    transition: width var(--transition-speed) ease;
}

.nav-links a:hover::after {
    width: 100%;
}

/* 导航栏中的按钮样式修复 */
.nav-links a.btn-primary {
    padding: 10px 20px;
    color: #fff;
    background-color: var(--primary-color);
    border-radius: 5px;
    margin-left: 5px;
}

.nav-links a.btn-primary:hover, 
.nav-links a.btn-primary:focus {
    background-color: #E68A00;
    color: #fff;
    transform: translateY(-3px);
    box-shadow: 0 4px 8px rgba(255, 153, 0, 0.3);
}

/* 移除导航按钮的下划线效果 */
.nav-links a.btn-primary::after {
    display: none;
}

/* 英雄区域优化 */
.hero {
    padding: 180px 0 100px;
    background: linear-gradient(to right, #f8f9fa, #e9ecef);
    position: relative;
    overflow: hidden;
}

/* 给英雄区域添加波浪效果 */
.hero::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 50px;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 120" preserveAspectRatio="none"><path d="M0,0V46.29c47.79,22.2,103.59,32.17,158,28,70.36-5.37,136.33-33.31,206.8-37.5C438.64,32.43,512.34,53.67,583,72.05c69.27,18,138.3,24.88,209.4,13.08,36.15-6,69.85-17.84,104.45-29.34C989.49,25,1113-14.29,1200,52.47V0Z" opacity=".25" fill="%23ffffff"/><path d="M0,0V15.81C13,36.92,27.64,56.86,47.69,72.05,99.41,111.27,165,111,224.58,91.58c31.15-10.15,60.09-26.07,89.67-39.8,40.92-19,84.73-46,130.83-49.67,36.26-2.85,70.9,9.42,98.6,31.56,31.77,25.39,62.32,62,103.63,73,40.44,10.79,81.35-6.69,119.13-24.28s75.16-39,116.92-43.05c59.73-5.85,113.28,22.88,168.9,38.84,30.2,8.66,59,6.17,87.09-7.5,22.43-10.89,48-26.93,60.65-49.24V0Z" opacity=".5" fill="%23ffffff"/><path d="M0,0V5.63C149.93,59,314.09,71.32,475.83,42.57c43-7.64,84.23-20.12,127.61-26.46,59-8.63,112.48,12.24,165.56,35.4C827.93,77.22,886,95.24,951.2,90c86.53-7,172.46-45.71,248.8-84.81V0Z" fill="%23ffffff"/></svg>');
    background-size: cover;
}

.hero .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative; /* 确保内容在波浪上方 */
    z-index: 2;
}

.hero-content {
    flex: 1;
    padding-right: 50px;
}

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    color: var(--dark-color);
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    color: #666;
    max-width: 600px;
}

.hero-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap; /* 移动设备支持 */
}

.hero-image {
    flex: 1;
    text-align: center;
    animation: float 6s ease-in-out infinite; /* 添加轻微浮动动画 */
}

@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-15px); }
    100% { transform: translateY(0px); }
}

.hero-image img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
}

/* 功能部分优化 */
.features {
    padding: 100px 0;
    background-color: #fff;
    position: relative;
}

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

.feature-card {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
    box-shadow: var(--box-shadow);
    transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
    border: 1px solid rgba(0,0,0,0.05);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: var(--primary-color);
    transition: transform var(--transition-speed) ease;
}

.feature-card:hover .feature-icon {
    transform: scale(1.1);
}

.feature-card h3 {
    font-size: 1.5rem;
    color: var(--dark-color);
    margin-bottom: 15px;
}

/* 使用场景部分优化 */
.use-cases {
    padding: 100px 0;
    background-color: var(--light-color);
    position: relative;
}

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

.use-case-card {
    background-color: #fff;
    border-radius: 10px;
    padding: 30px;
    box-shadow: var(--box-shadow);
    transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
    height: 100%; /* 确保卡片高度一致 */
}

.use-case-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.use-case-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: var(--secondary-color);
    transition: transform var(--transition-speed) ease;
}

.use-case-card:hover .use-case-icon {
    transform: scale(1.1);
}

/* 用户好处部分优化 */
.benefits {
    padding: 100px 0;
    background-color: #fff;
    position: relative;
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.benefit-card {
    background-color: var(--light-color);
    border-radius: 10px;
    padding: 30px;
    box-shadow: var(--box-shadow);
    transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
    height: 100%; /* 确保卡片高度一致 */
    border: 1px solid rgba(0,0,0,0.03);
}

.benefit-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.benefit-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: var(--success-color);
    transition: transform var(--transition-speed) ease;
}

.benefit-card:hover .benefit-icon {
    transform: scale(1.1);
}

/* FAQ部分优化 */
.faq {
    padding: 100px 0;
    background-color: var(--light-color);
}

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

.faq-item {
    background-color: #fff;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: var(--box-shadow);
    overflow: hidden;
    transition: all var(--transition-speed) ease;
    border: 1px solid rgba(0,0,0,0.05);
}

.faq-item:hover {
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.faq-question {
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: background-color var(--transition-speed) ease;
}

.faq-question:hover {
    background-color: rgba(0,0,0,0.02);
}

.faq-question h3 {
    margin-bottom: 0;
    font-size: 1.3rem;
    transition: color var(--transition-speed) ease;
}

.faq-item:hover .faq-question h3 {
    color: var(--primary-color);
}

.faq-toggle {
    font-size: 1.2rem;
    color: var(--primary-color);
    transition: transform var(--transition-speed) ease;
}

.faq-answer {
    padding: 0 20px 20px;
    display: none;
    line-height: 1.7;
}

.faq-item.active {
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.faq-item.active .faq-answer {
    display: block;
    animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.faq-item.active .faq-toggle i {
    transform: rotate(45deg);
}

/* 下载部分优化 */
.download {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--dark-color) 0%, #3a4a5f 100%);
    color: #fff;
    text-align: center;
    position: relative;
    overflow: hidden;
}

/* 添加动态背景效果 */
.download::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100" viewBox="0 0 100 100"><rect fill="none" width="100" height="100"/><rect fill="rgba(255,255,255,0.05)" width="50" height="50"/><rect fill="rgba(255,255,255,0.05)" x="50" y="50" width="50" height="50"/></svg>');
    opacity: 0.3;
}

.download .section-title {
    color: #fff;
}

.download-content {
    max-width: 600px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}

.download-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    color: rgba(255,255,255,0.9);
}

.version-info {
    margin-top: 20px;
    font-size: 0.9rem;
    opacity: 0.8;
}

/* 页脚优化 */
footer {
    padding: 80px 0 20px;
    background-color: var(--dark-color);
    color: #fff;
    position: relative;
}

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

.footer-logo .logo {
    margin-bottom: 15px;
}

.footer-links h4, .footer-contact h4 {
    margin-bottom: 20px;
    font-size: 1.2rem;
    color: #fff;
    position: relative;
    display: inline-block;
}

.footer-links h4::after, .footer-contact h4::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -8px;
    width: 30px;
    height: 2px;
    background-color: var(--primary-color);
}

.footer-links ul li {
    margin-bottom: 10px;
}

.footer-links ul li a {
    color: #ccc;
    transition: color var(--transition-speed) ease;
    padding: 2px 0;
}

.footer-links ul li a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-contact a {
    color: #ccc;
    transition: color var(--transition-speed) ease;
}

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

.social-icons {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-icons a {
    display: inline-flex;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    justify-content: center;
    align-items: center;
    transition: all var(--transition-speed) ease;
}

.social-icons a:hover {
    background-color: var(--primary-color);
    transform: translateY(-5px);
}

.social-icons i {
    font-size: 1.2rem;
    color: #fff;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 0.9rem;
    color: #ccc;
}

/* 响应式设计优化 */
@media (max-width: 1200px) {
    :root {
        --container-width: 960px;
    }
}

@media (max-width: 992px) {
    :root {
        --container-width: 720px;
    }
    
    html {
        font-size: 15px; /* 调整基础字体大小 */
    }
    
    .hero .container {
        flex-direction: column;
    }
    
    .hero-content {
        padding-right: 0;
        margin-bottom: 50px;
        text-align: center;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-content h1 {
        font-size: 2.5rem;
    }
}

@media (max-width: 768px) {
    :root {
        --container-width: 540px;
    }
    
    html {
        font-size: 14px;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero-content h1 {
        font-size: 2.2rem;
    }
    
    .nav-links {
        display: none;
    }
    
    .features-grid, .use-cases-grid, .benefits-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-links h4::after, .footer-contact h4::after {
        left: 50%;
        transform: translateX(-50%);
    }
    
    .social-icons {
        justify-content: center;
    }
}

/* 打印样式优化 */
@media print {
    header, footer, .hero-buttons, .social-icons {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.5;
        color: #000;
        background-color: #fff;
    }
    
    a {
        color: #000;
        text-decoration: underline;
    }
    
    .hero, .features, .use-cases, .benefits, .faq, .download {
        padding: 20pt 0;
        page-break-inside: avoid;
    }
    
    .container {
        max-width: 100%;
        padding: 0;
    }
}

/* 用于SEO的跳过导航链接 - 用于键盘访问的可访问性 */
.skip-to-content {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px;
    z-index: 100;
    transition: top 0.3s;
}

.skip-to-content:focus {
    top: 0;
}

/* 性能优化 - 减少重绘和回流 */
img, video {
    max-width: 100%;
    height: auto;
    will-change: transform; /* 提示浏览器元素将改变 */
}

/* 设置图像懒加载的占位符样式 */
img[loading="lazy"] {
    opacity: 0;
    transition: opacity 0.5s;
}

img[loading="lazy"].loaded {
    opacity: 1;
}