/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* CSS 变量定义 */
:root {
    --primary-color: #1e3a8a;
    --secondary-color: #3b82f6;
    --dark-color: #1e293b;
    --light-color: #f8fafc;
    --gray-color: #64748b;
    --white: #ffffff;
    --transition: all 0.3s ease;
}

/* 基础样式 */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: var(--white);
}

html {
    scroll-behavior: smooth;
}

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: var(--transition);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: var(--dark-color);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--secondary-color);
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--secondary-color);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--dark-color);
    transition: var(--transition);
}

/* 主横幅 */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    text-align: center;
    padding: 0 20px;
}

.hero-content {
    max-width: 800px;
    animation: fadeInUp 1s ease;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    font-weight: 300;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 14px 40px;
    text-decoration: none;
    border-radius: 5px;
    font-weight: 600;
    transition: var(--transition);
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: transparent;
    border-color: var(--white);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

/* 区块通用样式 */
.section {
    padding: 80px 0;
}

.section-gray {
    background-color: var(--light-color);
}

.section-dark {
    background-color: var(--dark-color);
    color: var(--white);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: inherit;
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--gray-color);
}

.section-dark .section-subtitle {
    color: rgba(255, 255, 255, 0.8);
}

/* 关于我们 */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    color: var(--gray-color);
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

.stat-item {
    text-align: center;
    padding: 30px;
    background-color: var(--light-color);
    border-radius: 10px;
    transition: var(--transition);
}

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

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.1rem;
    color: var(--gray-color);
}

/* 核心业务 */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.service-card {
    background-color: var(--white);
    padding: 40px 30px;
    border-radius: 10px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid #e2e8f0;
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.service-icon {
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
}

.service-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.service-description {
    color: var(--gray-color);
    line-height: 1.8;
}

/* 企业优势 */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.advantage-item {
    position: relative;
    padding-left: 80px;
}

.advantage-number {
    position: absolute;
    left: 0;
    top: 0;
    font-size: 4rem;
    font-weight: 700;
    color: var(--light-color);
    line-height: 1;
}

.advantage-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.advantage-description {
    color: var(--gray-color);
    line-height: 1.8;
}

/* 联系我们 */
.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

.contact-item {
    display: flex;
    gap: 20px;
    align-items: flex-start;
    padding: 30px;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    transition: var(--transition);
}

.contact-item:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.contact-icon {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--secondary-color);
    border-radius: 50%;
}

.contact-details h4 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.contact-details p {
    color: rgba(255, 255, 255, 0.8);
}

.contact-details a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: var(--transition);
}

.contact-details a:hover {
    color: var(--white);
}

/* 页脚 */
.footer {
    background-color: #0f172a;
    color: rgba(255, 255, 255, 0.7);
    text-align: center;
    padding: 30px 0;
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    /* 导航栏 */
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        text-align: center;
        transition: var(--transition);
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.1);
        padding: 20px 0;
        gap: 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        padding: 15px 0;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    /* Hero */
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    /* Section */
    .section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 2rem;
    }

    .section-header {
        margin-bottom: 40px;
    }

    /* 关于我们 */
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    /* 服务卡片 */
    .services-grid {
        grid-template-columns: 1fr;
    }

    /* 优势 */
    .advantages-grid {
        grid-template-columns: 1fr;
    }

    .advantage-item {
        padding-left: 60px;
    }

    .advantage-number {
        font-size: 3rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .btn {
        padding: 12px 30px;
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .stat-number {
        font-size: 2.5rem;
    }
}