/* ========== 全局重置 & 基础 ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
    background-color: #f8f9fa;
    color: #1e2a3a;
    line-height: 1.8;
    font-size: 16px;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* ========== 颜色变量 ========== */
:root {
    --brand-blue: #1A3A6B;
    --brand-dark: #0f2847;
    --gray-600: #6B7A8F;
    --gray-300: #9AABB8;
    --gray-bg: #f8f9fa;
    --gold-accent: #C9A96E;
    --white: #ffffff;
    --shadow: 0 8px 30px rgba(0,0,0,0.08);
    --radius: 8px;
}

/* ========== 头部 & 导航 ========== */
.site-header {
    background: var(--white);
    box-shadow: 0 2px 16px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
    height: 72px;
    display: flex;
    align-items: center;
}

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

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--brand-blue);
    letter-spacing: 2px;
}
.logo span {
    color: var(--gold-accent);
}

.nav-list {
    display: flex;
    gap: 36px;
    font-weight: 500;
}
.nav-list a {
    transition: color 0.2s;
}
.nav-list a:hover,
.nav-list a.active {
    color: var(--brand-blue);
}
.nav-list a.active {
    border-bottom: 3px solid var(--brand-blue);
    padding-bottom: 4px;
}

.header-phone {
    font-size: 18px;
    font-weight: 600;
    color: var(--brand-blue);
}
.header-phone i {
    margin-right: 6px;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}
.menu-toggle span {
    width: 28px;
    height: 3px;
    background: var(--brand-blue);
    border-radius: 2px;
}

/* ========== 底部 ========== */
.site-footer {
    background: var(--brand-dark);
    color: rgba(255,255,255,0.8);
    padding: 48px 0 24px;
    margin-top: 60px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr;
    gap: 40px;
    margin-bottom: 32px;
}
.footer-brand p {
    margin: 12px 0;
    font-size: 14px;
    opacity: 0.7;
}
.footer-links h4,
.footer-contact h4 {
    color: #fff;
    margin-bottom: 16px;
    font-weight: 600;
}
.footer-links a {
    display: block;
    padding: 4px 0;
    font-size: 14px;
    opacity: 0.7;
    transition: opacity 0.2s;
}
.footer-links a:hover {
    opacity: 1;
}
.footer-contact p {
    font-size: 14px;
    padding: 4px 0;
    opacity: 0.7;
}
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 20px;
    display: flex;
    justify-content: space-between;
    font-size: 13px;
    opacity: 0.6;
}
.footer-bottom .links a {
    margin-left: 20px;
}

/* ========== 按钮 ========== */
.btn-primary {
    display: inline-block;
    background: var(--brand-blue);
    color: #fff;
    padding: 14px 40px;
    border-radius: 40px;
    font-weight: 600;
    transition: background 0.3s, transform 0.1s;
    border: none;
    cursor: pointer;
    font-size: 16px;
}
.btn-primary:hover {
    background: var(--brand-dark);
    transform: translateY(-2px);
}
.btn-outline {
    display: inline-block;
    border: 2px solid var(--brand-blue);
    color: var(--brand-blue);
    padding: 12px 36px;
    border-radius: 40px;
    font-weight: 600;
    transition: 0.3s;
}
.btn-outline:hover {
    background: var(--brand-blue);
    color: #fff;
}

/* ========== 通用标题 ========== */
.section-title {
    text-align: center;
    margin-bottom: 48px;
}
.section-title h2 {
    font-size: 36px;
    color: var(--brand-blue);
    font-weight: 700;
}
.section-title p {
    color: var(--gray-600);
    margin-top: 8px;
    font-size: 18px;
}

/* ========== 首页 KV ========== */
.hero {
    background: linear-gradient(135deg, var(--brand-dark) 0%, #1e3a5f 100%);
    color: #fff;
    padding: 80px 0 100px;
    position: relative;
    overflow: hidden;
}
.hero::after {
    content: '';
    position: absolute;
    right: -10%;
    top: -10%;
    width: 50%;
    height: 130%;
    background: url('../assets/hero-bg.jpg') no-repeat center/cover;
    opacity: 0.25;
    z-index: 0;
}
.hero .container {
    position: relative;
    z-index: 1;
}
.hero h1 {
    font-size: 52px;
    font-weight: 700;
    letter-spacing: 2px;
}
.hero h1 span {
    color: var(--gold-accent);
}
.hero .sub {
    font-size: 22px;
    margin: 16px 0 12px;
    opacity: 0.9;
}
.hero .desc {
    font-size: 18px;
    opacity: 0.7;
    max-width: 600px;
    margin-bottom: 32px;
}
.hero .btn-primary {
    background: var(--gold-accent);
    color: #1e2a3a;
}
.hero .btn-primary:hover {
    background: #b89a5c;
}

/* ========== 核心优势 ========== */
.advantages {
    padding: 80px 0;
    background: var(--white);
}
.advantage-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}
.advantage-item {
    text-align: center;
    padding: 24px 16px;
    border-radius: var(--radius);
    transition: 0.3s;
}
.advantage-item:hover {
    box-shadow: var(--shadow);
    transform: translateY(-6px);
}
.advantage-item .icon {
    font-size: 48px;
    margin-bottom: 16px;
}
.advantage-item h4 {
    font-size: 20px;
    color: var(--brand-blue);
    margin-bottom: 8px;
}
.advantage-item p {
    color: var(--gray-600);
    font-size: 14px;
}

/* ========== 业务概览 ========== */
.services-overview {
    padding: 80px 0;
    background: var(--gray-bg);
}
.service-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}
.service-card {
    background: #fff;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: 0.3s;
}
.service-card:hover {
    transform: translateY(-8px);
}
.service-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: #ddd; /* 占位 */
}
.service-card .content {
    padding: 24px;
}
.service-card .content h4 {
    font-size: 20px;
    color: var(--brand-blue);
}
.service-card .content p {
    color: var(--gray-600);
    margin: 12px 0;
    font-size: 14px;
}
.service-card .content a {
    color: var(--brand-blue);
    font-weight: 600;
}

/* ========== 精选案例 ========== */
.cases-showcase {
    padding: 80px 0;
    background: #fff;
}
.case-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}
.case-item {
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    height: 280px;
    background: #ccc;
    background-size: cover;
    background-position: center;
}
.case-item .overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 24px;
    background: linear-gradient(transparent, rgba(0,0,0,0.7));
    color: #fff;
}
.case-item .overlay h4 {
    font-size: 20px;
}
.case-item .overlay p {
    opacity: 0.8;
    font-size: 14px;
}

/* ========== 客户 Logo ========== */
.clients {
    padding: 60px 0;
    background: var(--gray-bg);
}
.logo-wall {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 40px 60px;
}
.logo-wall img {
    height: 50px;
    filter: grayscale(100%);
    opacity: 0.6;
    transition: 0.3s;
}
.logo-wall img:hover {
    filter: none;
    opacity: 1;
}

/* ========== 新闻动态 ========== */
.news-section {
    padding: 80px 0;
    background: #fff;
}
.news-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}
.news-item {
    border-bottom: 1px solid #eee;
    padding-bottom: 16px;
}
.news-item .date {
    color: var(--gray-300);
    font-size: 14px;
}
.news-item h4 {
    margin: 8px 0;
    font-size: 18px;
}
.news-item p {
    color: var(--gray-600);
    font-size: 14px;
}

/* ========== 其他页面公用 ========== */
.page-banner {
    background: var(--brand-dark);
    color: #fff;
    padding: 60px 0;
    text-align: center;
}
.page-banner h1 {
    font-size: 38px;
}
.page-banner p {
    opacity: 0.7;
    margin-top: 8px;
}

/* ========== 关于我们 ========== */
.about-story {
    padding: 60px 0;
}
.story-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}
.story-content img {
    width: 100%;
    border-radius: var(--radius);
}
.timeline {
    margin-top: 60px;
    position: relative;
    padding-left: 40px;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 10px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--brand-blue);
}
.timeline-item {
    margin-bottom: 40px;
}
.timeline-item .year {
    font-weight: 700;
    color: var(--brand-blue);
    font-size: 22px;
}
.timeline-item p {
    color: var(--gray-600);
}

/* ========== 服务详情 ========== */
.service-detail-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    padding: 40px 0;
}
.service-detail-item {
    background: #fff;
    padding: 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

/* ========== 案例筛选 ========== */
.filter-tabs {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin: 30px 0 40px;
}
.filter-tabs button {
    padding: 8px 24px;
    border-radius: 30px;
    border: 1px solid #ddd;
    background: transparent;
    cursor: pointer;
    transition: 0.2s;
}
.filter-tabs button.active,
.filter-tabs button:hover {
    background: var(--brand-blue);
    color: #fff;
    border-color: var(--brand-blue);
}

/* ========== 联系我们 ========== */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    padding: 50px 0;
}
.contact-info p {
    padding: 8px 0;
}
.contact-form input,
.contact-form textarea,
.contact-form select {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid #ddd;
    border-radius: 6px;
    margin-bottom: 16px;
    font-size: 16px;
}
.contact-form textarea {
    height: 120px;
}

/* ========== 客服弹窗 ========== */
.kf-btn {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 64px;
    height: 64px;
    background: var(--brand-blue);
    border-radius: 50%;
    color: #fff;
    font-size: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 4px 20px rgba(26,58,107,0.4);
    z-index: 999;
    transition: 0.3s;
}
.kf-btn:hover {
    transform: scale(1.1);
}
.kf-panel {
    position: fixed;
    bottom: 120px;
    right: 40px;
    width: 300px;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    padding: 24px;
    display: none;
    z-index: 1000;
}
.kf-panel.active {
    display: block;
}
.kf-panel h4 {
    margin-bottom: 16px;
    color: var(--brand-blue);
}
.kf-panel p {
    padding: 6px 0;
    font-size: 15px;
}

/* ========== 响应式 ========== */
@media (max-width: 992px) {
    .advantage-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .service-cards {
        grid-template-columns: 1fr 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
    .story-content {
        grid-template-columns: 1fr;
    }
    .contact-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .header-phone {
        display: none;
    }
    .nav-list {
        display: none;
        flex-direction: column;
        background: #fff;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        padding: 20px;
        box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    }
    .nav-list.open {
        display: flex;
    }
    .menu-toggle {
        display: flex;
    }

    .hero h1 {
        font-size: 32px;
    }
    .hero .sub {
        font-size: 18px;
    }

    .advantage-grid {
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }
    .service-cards {
        grid-template-columns: 1fr;
    }
    .case-grid {
        grid-template-columns: 1fr;
    }
    .news-list {
        grid-template-columns: 1fr;
    }
    .service-detail-grid {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    .footer-bottom {
        flex-direction: column;
        gap: 12px;
    }
    .kf-panel {
        right: 20px;
        width: 280px;
        bottom: 100px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 26px;
    }
    .section-title h2 {
        font-size: 28px;
    }
    .btn-primary {
        padding: 12px 28px;
    }
}