* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", sans-serif;
}
/* 全局样式 */
:root {
    --main-color: #2C68B2;
    --sub-color: #409EFF;
    --text-color: #333;
    --light-color: #f5f7fa;
}
body {
    color: var(--text-color);
    line-height: 1.6;
}
a {
    text-decoration: none;
    color: inherit;
}
ul {
    list-style: none;
}
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}
.section {
    padding: 60px 0;
}
.title {
    text-align: center;
    font-size: 32px;
    margin-bottom: 40px;
    color: var(--main-color);
    position: relative;
}
.title::after {
    content: "";
    width: 80px;
    height: 3px;
    background: var(--sub-color);
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
}

/* 导航栏 */
header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 999;
}
.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}
.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--main-color);
}
.nav-menu {
    display: flex;
    gap: 30px;
}
.nav-menu li a {
    font-weight: 500;
    transition: 0.3s;
    padding: 10px 15px;
    border-radius: 5px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100px;
}
.nav-menu li a:hover {
    color: #fff;
    background: var(--sub-color);
}

/* 移动端汉堡菜单 */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}
.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--main-color);
    transition: 0.3s;
}

/* 首页banner */
.banner {
    height: 500px;
    background: linear-gradient(rgba(44,104,178,0.8), rgba(44,104,178,0.9)), url('../images/大楼.png');
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    color: #fff;
    text-align: center;
    margin-top: 70px;
}
.banner-content h1 {
    font-size: 48px;
    margin-bottom: 20px;
}
.banner-content p {
    font-size: 20px;
    max-width: 800px;
    margin: 0 auto 30px;
}
.btn {
    display: inline-block;
    padding: 12px 30px;
    background: #fff;
    color: var(--main-color);
    border-radius: 5px;
    font-weight: bold;
    transition: 0.3s;
}
.btn:hover {
    background: var(--sub-color);
    color: #fff;
}

/* 关于我们 */
.about {
    background: var(--light-color);
}
.about-content {
    display: flex;
    gap: 40px;
    align-items: center;
}
.about-text {
    flex: 1;
}
.about-text p {
    margin-bottom: 15px;
    font-size: 16px;
}
.about-img {
    flex: 1;
}
.about-img img {
    width: 100%;
    border-radius: 10px;
}

/* 产品中心 */
.product-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
}
.product-item {
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}
.product-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}
.product-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: all 0.3s ease;
}
.product-item:hover img {
    transform: scale(1.05);
}
.product-info {
    padding: 20px;
}
.product-info h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--main-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.product-info p {
    font-size: 14px;
    color: #666;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* 核心优势 */
.advantage {
    background: var(--light-color);
}
.adv-list {
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
}
.adv-item {
    width: 250px;
    text-align: center;
    padding: 30px 20px;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}
.adv-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}
.adv-item h3 {
    margin: 15px 0;
    color: var(--main-color);
}

/* 发展历程 */
.timeline {
    position: relative;
    max-width: 1000px;
    margin: 0 auto;
}
.timeline::after {
    content: '';
    position: absolute;
    width: 6px;
    background: var(--sub-color);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -3px;
}
.time-item {
    padding: 10px 40px;
    position: relative;
    width: 50%;
}
.time-item::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    background: #fff;
    border: 4px solid var(--sub-color);
    border-radius: 50%;
    top: 15px;
    z-index: 1;
}
.left {
    left: 0;
}
.right {
    left: 50%;
}
.left::after {
    right: -13px;
}
.right::after {
    left: -13px;
}
.time-content {
    padding: 20px;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
}

/* 联系我们 */
.contact-content {
    display: flex;
    gap: 40px;
}
.contact-info {
    flex: 1;
}
.contact-info p {
    margin-bottom: 15px;
    font-size: 16px;
}
.contact-map {
    flex: 1;
}
.contact-map img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
}

/* 业务领域 */
.business {
    background: var(--light-color);
}
.business-content {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
}
.business-item {
    background: #fff;
    border-radius: 10px;
    padding: 30px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
    transition: 0.3s;
}
.business-item:hover {
    transform: translateY(-5px);
}
.business-item h3 {
    margin-bottom: 15px;
    color: var(--main-color);
}

/* 核心团队 */
.team {
    background: #fff;
}
.team-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
}
.team-item {
    background: var(--light-color);
    border-radius: 10px;
    padding: 30px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
    transition: 0.3s;
}
.team-item:hover {
    transform: translateY(-5px);
}
.team-item h3 {
    margin-bottom: 10px;
    color: var(--main-color);
}
.team-item p {
    margin-bottom: 5px;
    color: #666;
}

/* 底部 */
footer {
    background: #222;
    color: #fff;
    text-align: center;
    padding: 30px 0;
}

/* 响应式设计 */
@media (max-width: 768px) {
    /* 导航菜单 */
    .hamburger {
        display: flex;
    }
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--main-color);
        flex-direction: column;
        justify-content: flex-start;
        align-items: center;
        padding-top: 50px;
        gap: 30px;
        transition: 0.3s;
    }
    .nav-menu.active {
        left: 0;
    }
    .nav-menu li a {
        color: #fff;
        font-size: 20px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        max-width: 200px;
    }
    .nav-menu li a:hover {
        background: #fff;
        color: var(--main-color);
    }

    /* Banner */
    .banner {
        height: 400px;
    }
    .banner-content h1 {
        font-size: 32px;
    }
    .banner-content p {
        font-size: 16px;
    }

    /* 关于我们 */
    .about-content {
        flex-direction: column;
        gap: 30px;
    }

    /* 产品中心 */
    .product-list {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 20px;
    }

    /* 核心优势 */
    .adv-list {
        flex-direction: column;
        align-items: center;
    }
    .adv-item {
        width: 100%;
        max-width: 350px;
    }

    /* 时间线 */
    .timeline::after {
        left: 31px;
    }
    .time-item {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }
    .time-item::after {
        left: 15px;
    }
    .right {
        left: 0;
    }

    /* 联系我们 */
    .contact-content {
        flex-direction: column;
        gap: 30px;
    }
    .contact-map img {
        height: 250px;
    }

    /* 标题 */
    .title {
        font-size: 28px;
    }
}

@media (max-width: 480px) {
    .container {
        width: 95%;
    }
    .section {
        padding: 40px 0;
    }
    .banner {
        height: 350px;
    }
    .banner-content h1 {
        font-size: 28px;
    }
    .product-list {
        grid-template-columns: 1fr;
    }
    .business-content {
        grid-template-columns: 1fr;
    }
    .team-list {
        grid-template-columns: 1fr;
    }
}