/* ===== 全局变量 ===== */
:root {
    /* 主色系：深蓝科技商务风 */
    --primary: #1a56db;
    --primary-dark: #1442b0;
    --primary-light: #e8eefb;
    --accent: #f59e0b;
    --accent-light: #fef3c7;
    --text: #0f172a;
    --text-light: #475569;
    --text-lighter: #94a3b8;
    --bg: #ffffff;
    --bg-alt: #f1f5f9;
    --bg-dark: #0c1a3a;
    --bg-footer: #eef2f7;
    --border: #e2e8f0;
    --radius: 8px;
    --radius-lg: 16px;
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.05);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
    --transition: 0.3s ease;
}

/* ===== 基础样式 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }

/* ===== LOGO图片 ===== */
.logo-img {
    height: 44px; width: auto; object-fit: contain;
    transition: transform var(--transition);
}
.nav-logo:hover .logo-img { transform: scale(1.03); }
.footer-brand .logo-img { height: 52px; }

/* ===== 按钮 ===== */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 12px 28px; border-radius: var(--radius);
    font-size: 15px; font-weight: 500; cursor: pointer;
    transition: all var(--transition); border: 2px solid transparent;
}
.btn-primary {
    background: var(--primary); color: #fff; border-color: var(--primary);
}
.btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); transform: translateY(-2px); box-shadow: 0 4px 12px rgba(26,86,219,0.3); }
.btn-outline {
    background: transparent; color: var(--primary); border-color: var(--primary);
}
.btn-outline:hover { background: var(--primary); color: #fff; transform: translateY(-2px); }
.btn-full { width: 100%; }

/* ===== 导航栏 ===== */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: rgba(255,255,255,0.97); backdrop-filter: blur(12px);
    transition: all var(--transition);
    border-bottom: 1px solid transparent;
}
.navbar.scrolled { border-bottom: 1px solid var(--border); box-shadow: var(--shadow-md); }
.nav-container {
    max-width: 1200px; margin: 0 auto; padding: 0 24px;
    display: flex; align-items: center; justify-content: space-between;
    height: 72px;
}
.nav-logo { display: flex; align-items: center; }
.nav-links { display: flex; list-style: none; gap: 24px; }
.nav-links a { color: var(--text-light); font-size: 14px; font-weight: 500; position: relative; }
.nav-links a::after {
    content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 2px;
    background: var(--primary); transition: width var(--transition);
}
.nav-links a:hover { color: var(--primary); }
.nav-links a:hover::after { width: 100%; }
.nav-toggle {
    display: none; background: none; border: none; cursor: pointer;
    flex-direction: column; gap: 5px; padding: 4px;
}
.nav-toggle span {
    display: block; width: 22px; height: 2px; background: var(--text);
    transition: all var(--transition); border-radius: 2px;
}

/* ===== Hero ===== */
.hero {
    position: relative; min-height: 100vh;
    display: flex; align-items: center; justify-content: center;
    padding: 120px 24px 80px;
    background: url('../images/Background.jpg') center/cover no-repeat;
    overflow: hidden;
}
.hero::after {
    content: ''; position: absolute; inset: 0;
    background: rgba(12, 26, 58, 0.55);
    z-index: 0;
}
.hero-content { text-align: center; max-width: 720px; z-index: 1; }
.hero-title {
    font-size: clamp(36px, 5vw, 64px); font-weight: 800;
    color: #ffffff; letter-spacing: -1px; line-height: 1.15;
}
.hero-subtitle {
    font-size: clamp(16px, 2vw, 20px); color: rgba(255,255,255,0.8);
    margin: 24px 0 40px; line-height: 1.7;
}
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero .btn-primary {
    background: #fff; color: var(--primary); border-color: #fff;
}
.hero .btn-primary:hover { background: var(--accent); color: #fff; border-color: var(--accent); }
.hero .btn-outline {
    background: transparent; color: #fff; border-color: rgba(255,255,255,0.6);
}
.hero .btn-outline:hover { background: rgba(255,255,255,0.15); color: #fff; border-color: #fff; }
.hero-bg-shapes { position: absolute; inset: 0; pointer-events: none; }
.shape { position: absolute; border-radius: 50%; }
.shape-1 {
    width: 500px; height: 500px; top: -150px; right: -100px;
    background: radial-gradient(circle, rgba(245,158,11,0.15), transparent 70%);
}
.shape-2 {
    width: 350px; height: 350px; bottom: -80px; left: -50px;
    background: radial-gradient(circle, rgba(26,86,219,0.2), transparent 70%);
}
.shape-3 {
    width: 250px; height: 250px; top: 40%; left: 60%;
    background: radial-gradient(circle, rgba(255,255,255,0.05), transparent 70%);
}

/* ===== Section通用 ===== */
.section { padding: 100px 0; }
.section-alt { background: var(--bg-alt); }
.section-header { text-align: center; max-width: 600px; margin: 0 auto 60px; }
.section-tag {
    display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: 3px;
    color: var(--primary); background: var(--primary-light);
    padding: 4px 16px; border-radius: 20px; margin-bottom: 16px;
}
.section-title {
    font-size: clamp(28px, 3.5vw, 36px); font-weight: 800; color: var(--text);
    margin-bottom: 12px; letter-spacing: -0.5px;
}
.section-desc { font-size: 16px; color: var(--text-light); line-height: 1.7; }

/* ===== 关于我们 ===== */
.about-grid {
    display: grid; grid-template-columns: 1fr 1.5fr; gap: 48px; align-items: start;
}
.about-stats {
    display: grid; grid-template-columns: 1fr 1fr; gap: 24px;
    background: var(--bg-dark); color: #fff; padding: 40px;
    border-radius: var(--radius-lg);
}
.stat-item { text-align: center; }
.stat-number { font-size: 48px; font-weight: 800; color: var(--accent); display: inline; }
.stat-suffix { font-size: 24px; font-weight: 700; color: var(--accent); }
.stat-label { display: block; font-size: 14px; color: #94a3b8; margin-top: 4px; }
.about-text h3 { font-size: 20px; font-weight: 700; color: var(--text); margin-bottom: 12px; }
.about-text p { color: var(--text-light); margin-bottom: 24px; line-height: 1.8; }
.about-list { list-style: none; }
.about-list li {
    padding: 8px 0; color: var(--text-light); font-size: 15px;
    border-bottom: 1px solid var(--border); position: relative; padding-left: 20px;
}
.about-list li::before {
    content: ''; position: absolute; left: 0; top: 14px;
    width: 8px; height: 8px; border-radius: 50%; background: var(--primary);
}

/* ===== 核心竞争力 ===== */
.advantages-grid {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
}
.advantage-card {
    text-align: center; padding: 36px 24px; background: var(--bg);
    border-radius: var(--radius-lg); border: 1px solid var(--border);
    transition: all var(--transition);
}
.advantage-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary-light); }
.advantage-icon { font-size: 42px; margin-bottom: 16px; }
.advantage-name { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.advantage-desc { color: var(--text-light); font-size: 14px; line-height: 1.7; }

/* ===== 产品服务 ===== */
.services-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.service-card {
    background: var(--bg); padding: 32px; border-radius: var(--radius-lg);
    border: 1px solid var(--border); transition: all var(--transition);
    position: relative; overflow: hidden;
}
.service-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent)); opacity: 0; transition: opacity var(--transition);
}
.service-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary-light); }
.service-card:hover::before { opacity: 1; }
.service-icon { font-size: 36px; margin-bottom: 16px; }
.service-name { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.service-desc { color: var(--text-light); font-size: 14px; line-height: 1.7; margin-bottom: 16px; }
.service-tags { display: flex; gap: 8px; list-style: none; flex-wrap: wrap; }
.service-tags li {
    font-size: 12px; padding: 4px 10px; border-radius: 20px;
    background: var(--primary-light); color: var(--primary); font-weight: 500;
}

/* ===== 项目案例 ===== */
.cases-featured { margin-bottom: 48px; }
.cases-subtitle {
    font-size: 18px; font-weight: 700; color: var(--text);
    margin-bottom: 24px; display: flex; align-items: center; gap: 8px;
}
.cases-subtitle::before {
    content: ''; display: inline-block; width: 4px; height: 20px;
    background: var(--primary); border-radius: 2px;
}
.cases-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.case-card {
    background: var(--bg); border-radius: var(--radius-lg);
    border: 1px solid var(--border); overflow: hidden;
    transition: all var(--transition);
}
.case-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.case-cover {
    height: 160px; display: flex; align-items: flex-start; justify-content: flex-end;
    padding: 16px;
    background-size: cover; background-position: center; background-repeat: no-repeat;
}
.case-category {
    background: rgba(255,255,255,0.9); color: var(--text);
    padding: 4px 12px; border-radius: 20px; font-size: 12px; font-weight: 600;
}
.case-body { padding: 20px; }
.case-title { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.case-desc { color: var(--text-light); font-size: 13px; line-height: 1.6; margin-bottom: 12px; }
.case-meta { display: flex; gap: 6px; flex-wrap: wrap; }
.case-tag {
    font-size: 12px; padding: 3px 8px; border-radius: 20px;
    background: var(--bg-alt); color: var(--text-light); font-weight: 500;
}

/* 全部案例列表 */
.cases-list-section { margin-bottom: 48px; }
.cases-list {
    background: var(--bg); border-radius: var(--radius-lg);
    border: 1px solid var(--border); overflow: hidden;
}
.case-row {
    display: grid; grid-template-columns: 80px 1fr 1.2fr;
    gap: 16px; padding: 12px 20px; align-items: center;
    border-bottom: 1px solid var(--border);
    transition: background var(--transition);
}
.case-row:last-child { border-bottom: none; }
.case-row:hover { background: var(--primary-light); }
.case-industry {
    font-size: 12px; font-weight: 700; color: var(--primary);
    background: var(--primary-light); padding: 3px 8px;
    border-radius: 4px; text-align: center;
}
.case-name { font-size: 14px; font-weight: 600; color: var(--text); }
.case-detail { font-size: 13px; color: var(--text-light); }

/* 最新动态 */
.news-section { margin-top: 48px; }
.news-items { display: flex; gap: 24px; flex-wrap: wrap; }
.news-item {
    flex: 1; min-width: 280px; padding: 20px 24px;
    background: var(--bg); border-radius: var(--radius-lg);
    border: 1px solid var(--border); display: flex; align-items: center; gap: 12px;
    transition: all var(--transition);
}
.news-item:hover { box-shadow: var(--shadow-md); border-color: var(--primary-light); }
.news-badge {
    font-size: 11px; font-weight: 700; letter-spacing: 1px;
    background: var(--primary); color: #fff; padding: 3px 10px;
    border-radius: 4px;
}
.news-item p { font-size: 14px; color: var(--text); font-weight: 500; }

/* ===== 联系我们 ===== */
.contact-grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 48px; }
.contact-info { display: flex; flex-direction: column; gap: 20px; }
.contact-item {
    display: flex; gap: 16px; align-items: flex-start;
    padding: 18px; background: var(--bg); border-radius: var(--radius-lg);
    border: 1px solid var(--border);
}
.contact-icon { font-size: 28px; flex-shrink: 0; }
.contact-item h4 { font-size: 15px; font-weight: 700; margin-bottom: 4px; }
.contact-item p { font-size: 14px; color: var(--text-light); }
.contact-form { background: var(--bg); border-radius: var(--radius-lg); padding: 32px; border: 1px solid var(--border); }
.form-group { margin-bottom: 16px; }
.form-group input,
.form-group select,
.form-group textarea {
    width: 100%; padding: 12px 16px; border: 1px solid var(--border);
    border-radius: var(--radius); font-size: 14px; font-family: inherit;
    transition: border-color var(--transition); background: var(--bg-alt);
    outline: none;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(26,86,219,0.1); }
.form-group textarea { resize: vertical; }

/* ===== 页脚 ===== */
.footer { background: var(--bg-footer); color: #475569; padding: 60px 0 24px; }
.footer-grid {
    display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px;
    margin-bottom: 40px;
}
.footer-brand .nav-logo { color: var(--primary); }
.footer-brand .nav-logo:hover { opacity: 0.85; }
.footer-desc { color: #64748b; margin-top: 12px; font-size: 14px; }
.footer-links h4 { color: #1e293b; font-size: 15px; font-weight: 700; margin-bottom: 16px; }
.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 8px; }
.footer-links a { color: #475569; font-size: 14px; }
.footer-links a:hover { color: var(--primary); }
.footer-bottom {
    border-top: 1px solid #cbd5e1; padding-top: 24px;
    text-align: center; font-size: 13px; color: #64748b;
}

/* ===== 动画 ===== */
.fade-up {
    opacity: 0; transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-up.visible { opacity: 1; transform: translateY(0); }
.delay-1 { transition-delay: 0.15s; }
.delay-2 { transition-delay: 0.3s; }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .services-grid { grid-template-columns: repeat(2, 1fr); }
    .advantages-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .case-row { grid-template-columns: 70px 1fr 1fr; }
}
@media (max-width: 768px) {
    .nav-toggle { display: flex; }
    .nav-links {
        display: none; position: absolute; top: 72px; left: 0; right: 0;
        background: #fff; padding: 16px 24px; flex-direction: column;
        gap: 16px; border-bottom: 1px solid var(--border); box-shadow: var(--shadow-md);
    }
    .nav-links.open { 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(5px, -5px); }
    .about-grid { grid-template-columns: 1fr; }
    .services-grid { grid-template-columns: 1fr; }
    .advantages-grid { grid-template-columns: 1fr 1fr; }
    .cases-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .section { padding: 60px 0; }
    .hero { padding: 100px 24px 60px; }
    .case-row { grid-template-columns: 1fr; gap: 4px; }
    .case-industry { width: fit-content; }
    .case-name { font-weight: 700; }
    .news-items { flex-direction: column; }
    .logo-img { height: 36px; }
}
@media (max-width: 480px) {
    .about-stats { grid-template-columns: 1fr 1fr; padding: 24px; }
    .stat-number { font-size: 36px; }
    .hero-actions { flex-direction: column; }
    .hero-actions .btn { width: 100%; }
    .advantages-grid { grid-template-columns: 1fr; }
}