/* ===== 全局基础 ===== */
:root {
    --primary: #2563EB;
    --primary-light: #60A5FA;
    --primary-dark: #1D4ED8;
    --accent: #0EA5E9;
    --text-dark: #1E293B;
    --text-gray: #64748B;
    --text-light: #94A3B8;
    --bg-white: #FFFFFF;
    --bg-light: #F1F5F9;
    --bg-section: #F8FAFC;
    --border: #E2E8F0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

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

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

.section {
    padding: 100px 0;
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(226,232,240,0.6);
    transition: var(--transition);
    padding: 0 24px;
}

.navbar.scrolled {
    background: rgba(255,255,255,0.98);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--primary-dark);
    text-decoration: none;
}

.logo-text {
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-link {
    color: var(--text-gray);
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 4px 0;
}

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

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

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

.nav-toggle {
    display: none;
    font-size: 22px;
    color: var(--text-dark);
    cursor: pointer;
}

/* ===== Hero Banner ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #0F172A 0%, #1E3A5F 40%, #2563EB 100%);
    overflow: hidden;
    padding: 120px 24px 80px;
}

.hero-bg-animation {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.hero-circle {
    position: absolute;
    border-radius: 50%;
    opacity: 0.1;
}

.hero-circle.c1 {
    width: 600px;
    height: 600px;
    background: var(--primary-light);
    top: -200px;
    right: -100px;
    animation: floatCircle 20s ease-in-out infinite;
}

.hero-circle.c2 {
    width: 400px;
    height: 400px;
    background: var(--accent);
    bottom: -150px;
    left: -100px;
    animation: floatCircle 15s ease-in-out infinite reverse;
}

.hero-circle.c3 {
    width: 300px;
    height: 300px;
    background: white;
    top: 50%;
    left: 50%;
    animation: floatCircle 25s ease-in-out infinite;
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 60px 60px;
}

@keyframes floatCircle {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(50px, -30px) scale(1.05); }
    50% { transform: translate(-30px, 50px) scale(0.95); }
    75% { transform: translate(30px, 30px) scale(1.02); }
}

.hero-content {
    text-align: center;
    color: white;
    max-width: 800px;
    z-index: 2;
}

.hero-title {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: 2px;
}

.hero-subtitle {
    font-size: 20px;
    color: rgba(255,255,255,0.8);
    margin-bottom: 40px;
    font-weight: 300;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 60px;
}

.hero-stats {
    display: flex;
    gap: 48px;
    justify-content: center;
}

.stat-item {
    text-align: center;
}

.stat-num {
    font-size: 36px;
    font-weight: 800;
    display: inline;
}

.stat-unit {
    font-size: 24px;
    font-weight: 600;
}

.stat-label {
    display: block;
    font-size: 14px;
    color: rgba(255,255,255,0.7);
    margin-top: 4px;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: var(--radius-sm);
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(37,99,235,0.4);
}

.btn-outline {
    background: transparent;
    color: white;
    border-color: rgba(255,255,255,0.4);
}

.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: white;
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* ===== Section Header ===== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 36px;
    font-weight: 800;
    color: var(--text-dark);
    margin-bottom: 16px;
}

.section-divider {
    width: 60px;
    height: 4px;
    background: var(--primary);
    border-radius: 2px;
    margin: 16px auto;
}

.section-desc {
    font-size: 16px;
    color: var(--text-gray);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== 关于我们 ===== */
.about {
    background: var(--bg-white);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: start;
}

.about-text p {
    font-size: 16px;
    color: var(--text-gray);
    line-height: 1.8;
    margin-bottom: 16px;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
}

.feature-card {
    background: var(--bg-light);
    border-radius: var(--radius);
    padding: 28px 24px;
    transition: var(--transition);
    border: 1px solid var(--border);
}

.feature-card:hover {
    background: var(--bg-white);
    border-color: var(--primary-light);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 20px;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.feature-card p {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.6;
}

/* ===== 核心优势 ===== */
.advantages {
    background: var(--bg-section);
}

.advantages-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
}

.adv-card {
    background: var(--bg-white);
    border-radius: var(--radius);
    padding: 36px 32px;
    border: 1px solid var(--border);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.adv-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    opacity: 0;
    transition: var(--transition);
}

.adv-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.adv-card:hover::before {
    opacity: 1;
}

.adv-card-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
}

.adv-icon {
    width: 52px;
    height: 52px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 22px;
}

.adv-card-header h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-dark);
    flex: 1;
}

.adv-number {
    font-size: 32px;
    font-weight: 800;
    color: var(--primary);
    opacity: 0.2;
    font-family: 'Arial', sans-serif;
}

.adv-card p {
    font-size: 15px;
    color: var(--text-gray);
    line-height: 1.7;
}

/* ===== 核心业务 ===== */
.services {
    background: var(--bg-white);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.service-card {
    background: var(--bg-light);
    border-radius: var(--radius);
    padding: 36px 28px;
    transition: var(--transition);
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}

.service-card:nth-child(4), .service-card:nth-child(5) {
    /* 让最后两个卡片居中 */
}

.service-card:hover {
    background: var(--bg-white);
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.service-icon-wrap {
    margin-bottom: 20px;
}

.service-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 26px;
    transition: var(--transition);
}

.service-card:hover .service-icon {
    transform: scale(1.1);
    box-shadow: 0 4px 16px rgba(37,99,235,0.3);
}

.service-card h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.service-card p {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.7;
    margin-bottom: 20px;
}

.service-link {
    color: var(--primary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: var(--transition);
}

.service-link:hover {
    gap: 10px;
    color: var(--primary-dark);
}

/* ===== 合作客户 ===== */
.clients {
    background: var(--bg-section);
}

.clients-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.client-card {
    background: var(--bg-white);
    border-radius: var(--radius);
    padding: 32px 24px;
    text-align: center;
    border: 1px solid var(--border);
    transition: var(--transition);
    cursor: default;
}

.client-card:hover {
    border-color: var(--primary-light);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.client-logo {
    width: 72px;
    height: 72px;
    background: var(--bg-light);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-size: 28px;
    color: var(--primary);
    transition: var(--transition);
}

.client-card:hover .client-logo {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
}

.more-card .client-logo {
    background: var(--bg-light);
    color: var(--text-light);
}

.client-card h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-dark);
}

/* ===== 新闻动态 ===== */
.news {
    background: var(--bg-white);
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.news-card {
    background: var(--bg-light);
    border-radius: var(--radius);
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid var(--border);
}

.news-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.news-img {
    height: 200px;
    background: linear-gradient(135deg, #E0E7FF, #DBEAFE);
    display: flex;
    align-items: center;
    justify-content: center;
}

.news-img-placeholder {
    font-size: 48px;
    color: var(--primary);
    opacity: 0.3;
}

.news-content {
    padding: 24px;
}

.news-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 10px;
}

.news-date {
    font-size: 13px;
    color: var(--primary);
    font-weight: 600;
}

.news-source {
    font-size: 13px;
    color: var(--text-gray);
    font-weight: 500;
}

.news-views {
    font-size: 13px;
    color: var(--text-light);
    display: flex;
    align-items: center;
    gap: 4px;
}

.news-views i {
    font-size: 12px;
}

.news-content h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 10px;
    line-height: 1.4;
}

.news-content p {
    font-size: 14px;
    color: var(--text-gray);
    line-height: 1.6;
    margin-bottom: 16px;
}

.news-link {
    color: var(--primary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: var(--transition);
}

.news-link:hover {
    gap: 10px;
}

/* ===== 联系我们 ===== */
.contact {
    background: var(--bg-section);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-item {
    display: flex;
    gap: 20px;
    align-items: start;
    padding: 20px;
    background: var(--bg-white);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.contact-item:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 18px;
}

.contact-item h4 {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 4px;
}

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

.contact-form-wrap {
    background: var(--bg-white);
    border-radius: var(--radius);
    padding: 32px;
    border: 1px solid var(--border);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.form-row {
    display: flex;
    gap: 16px;
}

.form-row input, .contact-form input, .contact-form textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    color: var(--text-dark);
    background: var(--bg-light);
    transition: var(--transition);
    font-family: inherit;
}

.form-row input:focus, .contact-form input:focus, .contact-form textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--bg-white);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

.contact-form textarea {
    resize: vertical;
    min-height: 120px;
}

/* ===== 页脚 ===== */
.footer {
    background: #0F172A;
    color: white;
    padding: 60px 0 0;
}

.footer-top {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 48px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-brand p {
    font-size: 14px;
    color: rgba(255,255,255,0.6);
    line-height: 1.6;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.footer-col h4 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 16px;
    color: rgba(255,255,255,0.9);
}

.footer-col a {
    display: block;
    color: rgba(255,255,255,0.5);
    text-decoration: none;
    font-size: 14px;
    margin-bottom: 8px;
    transition: var(--transition);
}

.footer-col a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    padding: 24px 0;
    text-align: center;
    font-size: 14px;
    color: rgba(255,255,255,0.4);
}

.footer-bottom a {
    color: rgba(255,255,255,0.5);
    text-decoration: none;
}

.footer-bottom a:hover {
    color: var(--primary-light);
}

/* ===== 回到顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: var(--primary);
    color: white;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    cursor: pointer;
    opacity: 0;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
    box-shadow: 0 4px 16px rgba(37,99,235,0.3);
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}

/* ===== 动画 ===== */
.animate-in {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

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

[data-animate="fade-up"] {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-animate="fade-up"].animated {
    opacity: 1;
    transform: translateY(0);
}

[data-animate="fade-right"] {
    opacity: 0;
    transform: translateX(-40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-animate="fade-right"].animated {
    opacity: 1;
    transform: translateX(0);
}

[data-animate="fade-left"] {
    opacity: 0;
    transform: translateX(40px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-animate="fade-left"].animated {
    opacity: 1;
    transform: translateX(0);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 36px;
    }
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .advantages-grid {
        grid-template-columns: 1fr;
    }
    .clients-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    .footer-top {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    .footer-links {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 16px 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-md);
    }
    .nav-menu.open {
        display: flex;
    }
    .nav-toggle {
        display: block;
    }
    .hero-title {
        font-size: 28px;
    }
    .hero-subtitle {
        font-size: 16px;
    }
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }
    .about-content {
        grid-template-columns: 1fr;
    }
    .services-grid {
        grid-template-columns: 1fr;
    }
    .news-grid {
        grid-template-columns: 1fr;
    }
    .contact-grid {
        grid-template-columns: 1fr;
    }
    .clients-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .form-row {
        flex-direction: column;
    }
    .section-title {
        font-size: 28px;
    }
    .section {
        padding: 60px 0;
    }
    .footer-links {
        grid-template-columns: 1fr;
        gap: 24px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 24px;
    }
    .stat-num {
        font-size: 28px;
    }
    .btn {
        padding: 12px 24px;
        font-size: 14px;
    }
}