/* ==================== CSS 变量 ==================== */
:root {
    /* 颜色系统 */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #0f172a;
    --accent: #06b6d4;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-dark: #0f172a;
    
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --text-white: #ffffff;
    
    --border: #e2e8f0;
    --border-light: #f1f5f9;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* 间距 */
    --section-padding: 100px;
    --container-width: 1200px;
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition: 0.3s ease;
    --transition-slow: 0.5s 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: 'Noto Sans SC', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

ul {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

input,
textarea,
select {
    font-family: inherit;
    font-size: inherit;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ==================== 按钮 ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-size: 15px;
    font-weight: 500;
    border-radius: 8px;
    transition: all var(--transition);
    white-space: nowrap;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: transparent;
    color: var(--text-white);
    border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--text-white);
}

.btn-sm {
    padding: 8px 16px;
    font-size: 13px;
}

.btn-full {
    width: 100%;
}

/* ==================== 头部导航 ==================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-light);
    transition: all var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-sm);
}

.nav {
    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(--secondary);
}

.logo-img {
    height: 36px;
    width: auto;
}

.logo-icon {
    font-size: 28px;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: 6px;
    transition: all var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
    background: rgba(37, 99, 235, 0.08);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition);
}

/* ==================== 首屏横幅 ==================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--secondary) 0%, #1a365d 50%, #0c4a6e 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.5;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at 30% 20%, rgba(37, 99, 235, 0.3) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 80%, rgba(6, 182, 212, 0.2) 0%, transparent 50%);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 120px 0 80px;
}

.hero-badge {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(37, 99, 235, 0.3);
    border: 1px solid rgba(37, 99, 235, 0.5);
    border-radius: 50px;
    font-size: 14px;
    font-weight: 500;
    color: var(--accent);
    margin-bottom: 24px;
    animation: fadeInUp 0.6s ease;
}

.hero-title {
    margin-bottom: 24px;
    animation: fadeInUp 0.6s ease 0.1s both;
}

.hero-title-cn {
    display: block;
    font-size: clamp(32px, 6vw, 56px);
    font-weight: 700;
    color: var(--text-white);
    letter-spacing: 2px;
    margin-bottom: 8px;
}

.hero-title-en {
    display: block;
    font-size: clamp(16px, 2.5vw, 20px);
    font-weight: 400;
    color: rgba(255, 255, 255, 0.7);
    letter-spacing: 1px;
}

.hero-desc {
    font-size: clamp(16px, 2vw, 18px);
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.8;
    margin-bottom: 40px;
    animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 60px;
    animation: fadeInUp 0.6s ease 0.3s both;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    animation: fadeInUp 0.6s ease 0.4s both;
}

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

.stat-number {
    display: block;
    font-size: 48px;
    font-weight: 700;
    color: var(--accent);
    line-height: 1;
}

.stat-label {
    display: block;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    margin-top: 8px;
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.5);
    font-size: 12px;
    animation: bounce 2s infinite;
}

.hero-scroll svg {
    width: 20px;
    height: 20px;
}

/* ==================== 通用区块 ==================== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    font-size: 13px;
    font-weight: 600;
    color: var(--primary);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 12px;
}

.section-title {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: 16px;
}

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

/* ==================== 关于我们 ==================== */
.about {
    padding: var(--section-padding) 0;
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text {
    font-size: 17px;
    color: var(--text-secondary);
}

.about-text p {
    margin-bottom: 20px;
}

.about-text p:last-child {
    margin-bottom: 0;
}

.about-lead {
    font-size: 20px;
    color: var(--text-primary);
    line-height: 1.8;
}

.about-lead strong {
    color: var(--primary);
}

.about-features {
    display: grid;
    gap: 24px;
}

.feature-card {
    padding: 28px;
    background: var(--bg-primary);
    border-radius: 16px;
    border: 1px solid var(--border);
    transition: all var(--transition);
}

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

.feature-icon {
    font-size: 36px;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--secondary);
    margin-bottom: 8px;
}

.feature-card p {
    font-size: 15px;
    color: var(--text-secondary);
}

/* ==================== 产品中心 ==================== */
.products {
    padding: var(--section-padding) 0;
    background: var(--bg-primary);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
}

.product-card {
    position: relative;
    padding: 32px;
    background: var(--bg-primary);
    border-radius: 20px;
    border: 1px solid var(--border);
    transition: all var(--transition);
    overflow: hidden;
}

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

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

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

.product-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 4px 12px;
    font-size: 11px;
    font-weight: 600;
    border-radius: 20px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
}

.product-badge.free {
    background: rgba(16, 185, 129, 0.1);
    color: #059669;
}

.product-badge.hot {
    background: rgba(239, 68, 68, 0.1);
    color: #dc2626;
}

.product-badge.new {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
}

.product-image {
    width: 100%;
    height: 180px;
    margin-bottom: 20px;
    border-radius: 12px;
    overflow: hidden;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.product-image img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    transition: transform var(--transition);
}

.product-card:hover .product-image img {
    transform: scale(1.05);
}

.product-name {
    font-size: 22px;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: 4px;
}

.product-tagline {
    font-size: 14px;
    color: var(--primary);
    font-weight: 500;
    margin-bottom: 16px;
}

.product-desc {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}

.product-features {
    margin-bottom: 24px;
}

.product-features li {
    position: relative;
    padding-left: 20px;
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.product-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

.product-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 20px;
    border-top: 1px solid var(--border-light);
}

.product-platform {
    font-size: 13px;
    color: var(--text-light);
}

/* ==================== 技术服务 ==================== */
.services {
    padding: var(--section-padding) 0;
    background: var(--bg-secondary);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 28px;
}

.service-card {
    padding: 40px 32px;
    background: var(--bg-primary);
    border-radius: 16px;
    border: 1px solid var(--border);
    text-align: center;
    transition: all var(--transition);
}

.service-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.service-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 24px;
    padding: 14px;
    background: rgba(37, 99, 235, 0.1);
    border-radius: 12px;
    color: var(--primary);
}

.service-icon svg {
    width: 100%;
    height: 100%;
}

.service-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--secondary);
    margin-bottom: 12px;
}

.service-card p {
    font-size: 15px;
    color: var(--text-secondary);
}

/* ==================== 联系我们 ==================== */
.contact {
    padding: var(--section-padding) 0;
    background: var(--bg-primary);
}

.contact-cards {
    display: flex;
    justify-content: center;
    gap: 24px;
}

.contact-card {
    padding: 40px 32px;
    background: var(--bg-secondary);
    border-radius: 20px;
    text-align: center;
    transition: all var(--transition);
    border: 1px solid transparent;
    min-width: 240px;
    max-width: 300px;
    flex: 1;
}

.contact-card:hover {
    background: var(--bg-primary);
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.contact-card-icon {
    width: 72px;
    height: 72px;
    margin: 0 auto 20px;
    padding: 18px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 50%;
    color: var(--text-white);
    transition: transform var(--transition);
}

.contact-card:hover .contact-card-icon {
    transform: scale(1.1);
}

.contact-card-icon svg {
    width: 100%;
    height: 100%;
}

.contact-card-image {
    width: 100px;
    height: 100px;
    margin: 0 auto 20px;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.contact-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.contact-card:hover .contact-card-image {
    transform: scale(1.05);
}

.contact-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--secondary);
    margin-bottom: 8px;
}

.contact-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--secondary);
    color: var(--text-white);
    padding: 80px 0 0;
}

.footer-top {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    padding-bottom: 60px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 700;
    color: var(--text-white);
    margin-bottom: 20px;
}

.footer-desc {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.footer-column h4 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--text-white);
}

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

.footer-column ul li a {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition-fast);
}

.footer-column ul li a:hover {
    color: var(--accent);
}

.footer-bottom {
    padding: 24px 0;
    text-align: center;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
}

.footer-bottom p:first-child {
    margin-bottom: 8px;
}

/* ==================== 回到顶部 ==================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    color: var(--text-white);
    border-radius: 50%;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition);
    z-index: 999;
}

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

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

.back-to-top svg {
    width: 24px;
    height: 24px;
}

/* ==================== 动画 ==================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* ==================== 响应式 ==================== */
@media (max-width: 1024px) {
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .contact-cards {
        gap: 20px;
    }
    
    .contact-card {
        min-width: 200px;
        padding: 32px 24px;
    }
    
    .footer-top {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }
    
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        flex-direction: column;
        padding: 20px;
        gap: 4px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        display: block;
        padding: 12px 16px;
    }
    
    .nav-toggle {
        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);
    }
    
    .hero-stats {
        flex-wrap: wrap;
        gap: 40px;
    }
    
    .stat-number {
        font-size: 36px;
    }
    
    .contact-cards {
        flex-wrap: wrap;
        gap: 16px;
    }
    
    .contact-card {
        flex: 1;
        min-width: 180px;
        max-width: 280px;
        padding: 28px 20px;
    }
    
    .footer-links {
        grid-template-columns: 1fr 1fr;
    }
    
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .hero-actions .btn {
        width: 100%;
    }
    
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-cards {
        flex-direction: column;
        align-items: center;
        gap: 16px;
    }
    
    .contact-card {
        width: 100%;
        max-width: 320px;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    .contact-form {
        padding: 28px;
    }
}