/* 全局变量定义 - 方便后期改色 */
:root {
    --primary-color: #0056b3;
    /* 企业深蓝 */
    --accent-color: #00a8e8;
    /* 科技亮蓝 */
    --text-dark: #333333;
    /* 深色文字 */
    --text-light: #666666;
    /* 浅色文字 */
    --bg-light: #f8f9fa;
    /* 浅灰背景 */
    --white: #ffffff;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 5px 15px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    overflow-x: hidden;
}

body {
    font-family: 'Helvetica Neue', Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--white);
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    display: block;
}

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

/* 头部导航 */
/* 头部导航 - 高斯模糊版 */
header {
    /* 1. 关键：背景颜色必须半透明 (0.7-0.8 左右效果最佳) */
    background-color: rgba(255, 255, 255, 0.75);

    /* 2. 核心：背景模糊处理 */
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    /* 兼容 Safari/iOS */

    /* 3. 细节：为了让磨砂感更强，阴影可以调淡一点，并加一条微弱的边框 */
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.05);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);

    /* 保持原有的布局属性 */
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    height: 80px;
    display: flex;
    align-items: center;
    transition: all 0.3s ease;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    position: relative;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    font-size: 32px;
    color: var(--primary-color);
}

.logo-text h1 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 2px;
}

.logo-text p {
    font-size: 10px;
    color: var(--text-light);
    letter-spacing: 0.5px;
}

nav ul {
    display: flex;
    gap: 30px;
}

nav a {
    font-weight: 500;
    font-size: 16px;
    color: var(--text-dark);
    position: relative;
    padding: 5px 0;
}

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

nav a:hover,
nav a.active {
    color: var(--primary-color);
}

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

/* 咨询热线 */
.header-hotline {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 15px;
    white-space: nowrap;
}

.header-hotline i {
    font-size: 14px;
}

.mobile-menu-btn {
    display: none;
    font-size: 24px;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-dark);
}

/* 英雄区域 (Banner) */
.hero {
    height: 100vh;
    min-height: 600px;
    /* 替换为您的高清背景图 URL */
    background: linear-gradient(rgba(0, 30, 60, 0.8), rgba(0, 30, 60, 0.7)), url('../bc/bc_index.avif');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    display: flex;
    align-items: center;
    color: var(--white);
    padding-top: 80px;
}

.hero h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    animation: fadeInUp 0.8s ease;
}

.hero p {
    font-size: 20px;
    max-width: 700px;
    margin-bottom: 40px;
    opacity: 0.9;
    animation: fadeInUp 0.8s ease 0.2s backwards;
}

.cta-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--white);
    padding: 15px 40px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 18px;
    box-shadow: 0 4px 15px rgba(0, 86, 179, 0.4);
    animation: fadeInUp 0.8s ease 0.4s backwards;
}

.cta-button:hover {
    background-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 168, 232, 0.4);
}

/* 通用版块样式 */
section {
    padding: 80px 0;
}

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

.section-title h2 {
    font-size: 36px;
    margin-bottom: 15px;
    color: var(--text-dark);
    position: relative;
    display: inline-block;
}

.section-title h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: var(--primary-color);
    margin: 10px auto 0;
    border-radius: 2px;
}

.section-title p {
    color: var(--text-light);
    font-size: 18px;
    max-width: 600px;
    margin: 0 auto;
}

/* 业务领域 (Grid布局) */
.services {
    background-color: var(--bg-light);
}

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

.service-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border-bottom: 4px solid transparent;
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
    border-bottom-color: var(--primary-color);
}

.service-icon {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 25px;
    background: rgba(0, 86, 179, 0.1);
    width: 80px;
    height: 80px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.service-card:hover .service-icon {
    background: var(--primary-color);
    color: var(--white);
}

.service-content h3 {
    font-size: 22px;
    margin-bottom: 15px;
}

.service-content p {
    color: var(--text-light);
    margin-bottom: 20px;
    font-size: 15px;
}

.service-link {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 14px;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.service-link:hover {
    gap: 8px;
    color: var(--accent-color);
}

/* 关于我们 */
.about-content {
    display: flex;
    align-items: flex-start;
    gap: 60px;
}

.about-text {
    flex: 1;
    padding-top: 0;
    margin-top: -20px;
}

.about-text h2 {
    font-size: 32px;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.about-text p {
    margin-bottom: 20px;
    color: var(--text-light);
    text-align: justify;
}

.about-image {
    flex: 1;
    position: relative;
}

.about-image img {
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
}

.about-image::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    border: 10px solid var(--accent-color);
    top: -20px;
    left: -20px;
    z-index: -1;
    border-radius: 12px;
    opacity: 0.2;
}

/* 我们的优势 */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.advantage-item {
    text-align: center;
    padding: 30px;
    background: var(--white);
    border: 1px solid #eee;
    border-radius: 8px;
    transition: var(--transition);
}

.advantage-item:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.advantage-icon {
    font-size: 36px;
    color: var(--accent-color);
    margin-bottom: 20px;
}

.advantage-item h3 {
    margin-bottom: 10px;
    font-size: 18px;
}

.advantage-item p {
    font-size: 14px;
    color: var(--text-light);
}

/* 页脚 */
footer {
    background-color: #0f172a;
    /* 深邃的夜空蓝 */
    color: #cbd5e1;
    padding: 70px 0 20px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    gap: 50px;
    margin-bottom: 50px;
}

.footer-content .footer-column:first-child {
    max-width: 450px;
}

.footer-social {
    display: flex;
    gap: 70px;
    margin-top: 30px;
}

.footer-social img {
    width: 130px;
    height: 130px;
    border-radius: 4px;
    /* object-fit: cover; */
}

.footer-column h3 {
    color: var(--white);
    margin-bottom: 25px;
    font-size: 20px;
    position: relative;
    padding-bottom: 10px;
}

.footer-column h3::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 30px;
    height: 2px;
    background-color: var(--accent-color);
}

.footer-links li {
    margin-bottom: 12px;
}

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

.contact-info li {
    display: flex;
    align-items: flex-start;
    gap: 15px;
    margin-bottom: 20px;
}

.contact-info i {
    color: var(--accent-color);
    margin-top: 5px;
}

.copyright {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 20px;
    text-align: center;
    font-size: 14px;
    color: #64748b;
}

/* 简单动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

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

/* 响应式设计 (平板/手机) */
@media (max-width: 992px) {
    .about-content {
        flex-direction: column;
    }

    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    /* 修复iOS设备上background-attachment: fixed的问题 */
    .hero {
        background-attachment: scroll;
    }
}

@media (max-width: 768px) {
    .header-container {
        padding: 0 15px;
    }

    /* 移动端隐藏热线 */
    .header-hotline {
        display: none;
    }

    /* 移动端Logo优化 */
    .logo-text h1 {
        font-size: 14px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        max-width: 200px;
    }

    .logo-text p {
        display: none;
        /* 移动端隐藏英文名 */
    }

    .logo-icon img {
        width: 40px !important;
    }

    /* 移动端菜单 */
    .mobile-menu-btn {
        display: block !important;
        z-index: 1001;
        position: static;
        margin-left: auto;
    }

    #mainNav {
        position: fixed;
        top: 0;
        right: -100%;
        /* 默认隐藏在右侧 */
        width: 70%;
        max-width: 280px;
        height: 100vh;
        background-color: var(--white);
        box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
        padding-top: 80px;
        transition: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        display: block;
    }

    #mainNav.active {
        right: 0;
    }

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

    nav a {
        font-size: 18px;
    }

    .hero h2 {
        font-size: 28px;
        padding: 0 10px;
    }

    .hero p {
        font-size: 15px;
        padding: 0 15px;
    }

    .cta-button {
        padding: 12px 30px;
        font-size: 16px;
    }

    /* Footer优化 */
    .footer-content {
        flex-direction: column;
        gap: 30px;
    }

    .footer-social {
        gap: 30px;
    }

    .footer-social img {
        width: 100px;
        height: 100px;
    }

    /* 关于我们图片优化 */
    .about-image img {
        width: 100%;
        height: auto;
    }

    .about-image::before {
        display: none;
        /* 移动端隐藏装饰边框 */
    }

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

    section {
        padding: 50px 0;
    }

    .section-title h2 {
        font-size: 28px;
    }

    .section-title p {
        font-size: 15px;
        padding: 0 10px;
    }
}

@media (max-width: 480px) {
    .logo-text h1 {
        font-size: 12px;
        max-width: 150px;
    }

    .logo-icon img {
        width: 35px !important;
    }

    .hero h2 {
        font-size: 24px;
    }

    .hero p {
        font-size: 14px;
    }

    .footer-social img {
        width: 80px;
        height: 80px;
    }

    .footer-column h3 {
        font-size: 18px;
    }

    .contact-info li {
        font-size: 14px;
    }

    .copyright p {
        font-size: 12px;
    }
}