/* 
 * 北京小友友缘科技有限公司官网样式表
 * 响应式设计 - 适配移动端和桌面端
 */
/* ===== 全局样式重置 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
:root {
    /* 主色调 - 专业科技蓝 */
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    
    /* 中性色 */
    --text-dark: #1f2937;
    --text-gray: #6b7280;
    --text-light: #f3f4f6;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    
    /* 间距 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* 圆角 */
    --border-radius: 8px;
    --border-radius-lg: 12px;
    
    /* 阴影 */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    
    /* 过渡 */
    --transition: all 0.3s ease;
}
html {
    scroll-behavior: smooth;
}
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-white);
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}
/* ===== 头部导航 ===== */
.header {
    background-color: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}
.header.sticky {
    box-shadow: var(--shadow-md);
}
.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
}
.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
}
.logo a {
    color: var(--primary-color);
    text-decoration: none;
}
.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}
.nav-item a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    padding: var(--spacing-xs) 0;
    position: relative;
    transition: var(--transition);
}
.nav-item a:hover,
.nav-item.active a {
    color: var(--primary-color);
}
.nav-item.active a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
}
/* 汉堡菜单 - 移动端 */
.hamburger {
    display: none;
    cursor: pointer;
}
.hamburger .bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    background-color: var(--text-dark);
    transition: var(--transition);
}
/* ===== 主要内容区域 ===== */
main {
    margin-top: 80px;
    min-height: calc(100vh - 80px - 300px);
}
/* ===== 首页横幅 ===== */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--text-light);
    padding: 6rem 0;
    text-align: center;
}
.hero-content h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.8s ease;
}
.hero-content p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.95;
    animation: fadeInUp 1s ease;
}
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}
.btn-primary {
    background-color: var(--bg-white);
    color: var(--primary-color);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}
.btn-secondary {
    background-color: transparent;
    color: var(--bg-white);
    border: 2px solid var(--bg-white);
    margin-left: var(--spacing-sm);
}
.btn-secondary:hover {
    background-color: var(--bg-white);
    color: var(--primary-color);
}
/* ===== 特色区域 ===== */
.features {
    padding: var(--spacing-xl) 0;
    background-color: var(--bg-light);
}
.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: var(--spacing-xl);
    color: var(--text-dark);
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}
.feature-card {
    background-color: var(--bg-white);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}
.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}
.feature-icon {
    width: 60px;
    height: 60px;
    background-color: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}
.feature-icon span {
    color: white;
    font-size: 1.5rem;
}
.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
}
.feature-card p {
    color: var(--text-gray);
    line-height: 1.7;
}
/* ===== 关于我们页面 ===== */
.page-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 4rem 0 2rem;
}
.page-header h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}
.page-header p {
    font-size: 1.1rem;
    opacity: 0.9;
}
.content-section {
    padding: var(--spacing-xl) 0;
}
.about-content {
    max-width: 900px;
    margin: 0 auto;
}
.about-text {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-gray);
    margin-bottom: var(--spacing-lg);
}
/* 发展历程 */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 2rem auto;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: var(--primary-color);
    transform: translateX(-50%);
}
.timeline-item {
    position: relative;
    margin-bottom: 2rem;
}
.timeline-content {
    width: 45%;
    background: var(--bg-white);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
}
.timeline-item:nth-child(odd) .timeline-content {
    margin-right: auto;
}
.timeline-item:nth-child(even) .timeline-content {
    margin-left: auto;
}
.timeline-date {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 0.25rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}
/* 团队展示 */
.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}
.team-member {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--bg-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}
.team-member:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}
.team-avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background-color: var(--accent-color);
    margin: 0 auto var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2.5rem;
}
.team-member h4 {
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}
.team-position {
    color: var(--primary-color);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}
.team-desc {
    color: var(--text-gray);
    font-size: 0.9rem;
}
/* ===== 产品服务页面 ===== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}
.product-card {
    background: var(--bg-white);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}
.product-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}
.product-image {
    height: 200px;
    background: linear-gradient(135deg, var(--accent-color), var(--primary-color));
    display: flex;
    align-items: center;
    justify-content: center;
}
.product-image span {
    color: white;
    font-size: 3rem;
}
.product-content {
    padding: var(--spacing-md);
}
.product-content h3 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
}
.product-content p {
    color: var(--text-gray);
    margin-bottom: var(--spacing-md);
}
.product-features {
    list-style: none;
    margin-bottom: var(--spacing-md);
}
.product-features li {
    padding: 0.25rem 0;
    color: var(--text-gray);
}
.product-features li::before {
    content: '✓ ';
    color: var(--primary-color);
    font-weight: bold;
}
/* ===== 联系页面 ===== */
.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
}
.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}
.contact-item {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}
.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.contact-icon span {
    color: white;
    font-size: 1.25rem;
}
.contact-details h4 {
    margin-bottom: 0.25rem;
}
.contact-details p {
    color: var(--text-gray);
}
.map-container {
    width: 100%;
    height: 300px;
    border-radius: var(--border-radius);
    overflow: hidden;
    margin-top: var(--spacing-md);
}
.map-placeholder {
    width: 100%;
    height: 100%;
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-gray);
}
/* 联系表单 */
.contact-form {
    background: var(--bg-white);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
}
.form-group {
    margin-bottom: var(--spacing-md);
}
.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-dark);
}
.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #e5e7eb;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
}
.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}
.form-group textarea {
    min-height: 150px;
    resize: vertical;
}
/* ===== 页脚 ===== */
.footer {
    background-color: var(--text-dark);
    color: var(--text-light);
    padding: var(--spacing-xl) 0 var(--spacing-md);
}
.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}
.footer-section h3 {
    margin-bottom: var(--spacing-md);
    color: var(--bg-white);
}
.footer-section p,
.footer-section li {
    color: #9ca3af;
    line-height: 1.8;
}
.footer-section ul {
    list-style: none;
}
.footer-section ul li a {
    color: #9ca3af;
    text-decoration: none;
    transition: var(--transition);
}
.footer-section ul li a:hover {
    color: var(--bg-white);
    padding-left: 5px;
}
.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: var(--spacing-md);
    text-align: center;
    color: #9ca3af;
}
/* ===== 动画效果 ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}
/* ===== 响应式设计 - 移动端适配 ===== */
@media (max-width: 768px) {
    .hamburger {
        display: block;
    }
    
    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }
    
    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg-white);
        width: 100%;
        text-align: center;
        transition: var(--transition);
        box-shadow: 0 10px 15px rgba(0,0,0,0.1);
        padding: var(--spacing-lg) 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hero {
        padding: 4rem 0;
    }
    
    .hero-content h2 {
        font-size: 2rem;
    }
    
    .hero-content p {
        font-size: 1rem;
    }
    
    .btn {
        display: block;
        margin: var(--spacing-sm) auto;
        width: fit-content;
    }
    
    .btn-secondary {
        margin-left: auto;
    }
    
    .contact-container,
    .timeline::before {
        grid-template-columns: 1fr;
    }
    
    .timeline::before {
        left: 30px;
    }
    
    .timeline-content {
        width: calc(100% - 60px);
        margin-left: 60px !important;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}
@media (max-width: 480px) {
    :root {
        --spacing-xl: 2rem;
        --spacing-lg: 1.5rem;
    }
    
    .hero-content h2 {
        font-size: 1.75rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
}