/* 基础重置 */
:root {
    --primary-color: #0066cc;
    --secondary-color: #003366;
    --accent-color: #00bcd4;
    --text-color: #333;
    --light-text: #666;
    --bg-light: #f9f9f9;
    --white: #ffffff;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Noto Sans SC', sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

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

.section {
    padding: 80px 0;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 4px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

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

.primary-btn:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 102, 204, 0.3);
}

/* 导航栏 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    padding: 15px 0;
}

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

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

.logo img {
    height: 40px;
    width: auto;
}

.logo h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--secondary-color);
}

.nav-list {
    display: flex;
    gap: 30px;
}

.nav-list a {
    font-weight: 500;
    color: var(--text-color);
    position: relative;
    padding-bottom: 5px;
}

.nav-list a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-list a:hover::after,
.nav-list a.active::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.mobile-menu-btn span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    border-radius: 2px;
}

/* Hero Section */
.hero {
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: flex-start; /* 左对齐 */
    position: relative;
    padding-top: 60px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    z-index: -1;
}

/* 简单的动态背景效果 */
.hero-bg::before {
    content: '';
    position: absolute;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(0, 102, 204, 0.1) 0%, rgba(255,255,255,0) 70%);
    top: -200px;
    right: -200px;
    border-radius: 50%;
}

.hero-content {
    width: 100%;
}

.hero h2 {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 20px;
    color: var(--secondary-color);
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 40px;
    color: var(--light-text);
    max-width: 600px;
}

/* 动画类 */
.animate-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 通用 Section 样式 */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h3 {
    font-size: 2rem;
    color: var(--secondary-color);
    margin-bottom: 10px;
}

.section-header p {
    font-size: 0.9rem;
    color: var(--accent-color);
    font-weight: 700;
    letter-spacing: 2px;
}

.section-header .line {
    width: 60px;
    height: 3px;
    background: var(--primary-color);
    margin: 15px auto 0;
}

/* 关于我们 */
.about {
    background: var(--white);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h4 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.about-text p {
    margin-bottom: 15px;
    color: var(--light-text);
}

.stats {
    display: flex;
    gap: 40px;
    margin-top: 30px;
}

.stats li {
    display: flex;
    flex-direction: column;
}

.stats .number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--secondary-color);
}

.stats .label {
    font-size: 0.9rem;
    color: var(--light-text);
}

.about-img-box {
    width: 100%;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.about-img-box:hover {
    transform: scale(1.02);
}

.image-placeholder {
    width: 100%;
    height: 400px;
    background: #eee;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 10px;
    background: linear-gradient(45deg, #e6e9f0 0%, #eef1f5 100%);
    box-shadow: var(--shadow);
}

/* 解决方案 */
.solutions {
    background: var(--bg-light);
}

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

.card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: var(--transition);
    text-align: center;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.1);
}

.card .icon {
    margin-bottom: 20px;
    color: var(--primary-color);
}

.card h4 {
    font-size: 1.25rem;
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.card p {
    font-size: 0.95rem;
    color: var(--light-text);
}

/* 产品与服务 */
.products {
    background: var(--white);
}

.product-item {
    display: flex;
    align-items: center;
    gap: 50px;
    margin-bottom: 80px;
}

.product-item.reverse {
    flex-direction: row-reverse;
}

.product-item:last-child {
    margin-bottom: 0;
}

.product-info {
    flex: 1;
}

.product-info h4 {
    font-size: 1.75rem;
    margin-bottom: 10px;
    color: var(--secondary-color);
}

.product-info .tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(0, 102, 204, 0.1);
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 20px;
}

.product-info p {
    margin-bottom: 20px;
    color: var(--light-text);
}

.features li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 10px;
    color: var(--text-color);
}

.features li::before {
    content: '•';
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

.product-img-box {
    flex: 1;
    display: flex;
    justify-content: center;
}

.product-img-box-img {
    max-width: 100%;
    max-height: 400px;
    border-radius: 20px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.product-img-box-img:hover {
    transform: translateY(-5px);
}

.reverse .product-img-box-img {
     max-height: 400px;
     border: 4px solid #111;
     border-radius: 20px;
}

/* 联系我们 */
.contact {
    background: linear-gradient(rgba(0,51,102,0.9), rgba(0,51,102,0.9)), url('https://source.unsplash.com/random/1600x900?technology') center/cover;
    color: var(--white);
    padding: 80px 0;
}

.contact .section-header h3,
.contact .section-header p {
    color: var(--white);
}
.contact .section-header .line {
    background: var(--accent-color);
}

.contact-wrapper {
    display: flex;
    gap: 50px;
    background: var(--white);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.contact-info {
    flex: 1;
    background: var(--primary-color);
    padding: 50px;
    color: var(--white);
}

.contact-info h5 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    margin-top: 30px;
}

.contact-info h5:first-child {
    margin-top: 0;
}

.contact-form-mock {
    flex: 1.5;
    padding: 50px;
}

.contact-form-mock input,
.contact-form-mock textarea {
    width: 100%;
    padding: 12px;
    margin-bottom: 20px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-family: inherit;
}

.contact-form-mock textarea {
    resize: vertical;
}

/* Footer */
.footer {
    background: #1a1a1a;
    color: #999;
    padding: 40px 0 20px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 1px solid #333;
}

.footer-logo h2 {
    color: var(--white);
    margin-bottom: 5px;
}

.footer-links a {
    margin-left: 20px;
    color: #999;
}

.footer-links a:hover {
    color: var(--white);
}

.copyright {
    text-align: center;
    font-size: 0.85rem;
}

/* 响应式 */
@media (max-width: 768px) {
    .header .nav-list {
        display: none; /* 简化版：这里未实现完整的移动端菜单展开 */
    }
    
    .nav-list.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 70px;
        right: 0;
        background: var(--white);
        width: 100%;
        padding: 20px;
        box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    }
    
    .mobile-menu-btn {
        display: flex;
    }

    .hero-content h2 {
        font-size: 2.5rem;
    }
    
    .about-grid,
    .product-item,
    .product-item.reverse,
    .contact-wrapper {
        flex-direction: column;
        gap: 30px;
        grid-template-columns: 1fr;
    }
    
    .contact-info, .contact-form-mock {
        padding: 30px;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }
    
    .footer-links a {
        margin: 0 10px;
    }
}