/* ==========================================
   纳海川科技 - 高端企业网站样式
   ========================================== */

/* 变量定义 */
:root {
    --primary-color: #667eea;
    --primary-dark: #5a67d8;
    --secondary-color: #764ba2;
    --accent-color: #f6ad55;
    --text-dark: #1a202c;
    --text-gray: #4a5568;
    --text-light: #718096;
    --bg-light: #f7fafc;
    --bg-white: #ffffff;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    --gradient-card: linear-gradient(145deg, #ffffff 0%, #f7fafc 100%);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 60px rgba(0,0,0,0.15);
    --border-radius: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    font-weight: 400;
    line-height: 1.7;
    color: var(--text-dark);
    background: var(--bg-white);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* ==========================================
   导航栏
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 20px 0;
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    padding: 12px 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--bg-white);
    text-decoration: none;
    transition: var(--transition);
}

.navbar.scrolled .nav-brand {
    color: var(--primary-color);
}

.nav-brand i {
    font-size: 24px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.navbar.scrolled .nav-links a {
    color: var(--text-dark);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent-color);
}

.nav-links a:not(.btn-nav)::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: width 0.3s;
}

.nav-links a:hover::after {
    width: 100%;
}

.btn-nav {
    background: rgba(255, 255, 255, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.3);
    padding: 8px 20px;
    border-radius: 50px;
    backdrop-filter: blur(10px);
}

.navbar.scrolled .btn-nav {
    background: var(--gradient-primary);
    border-color: transparent;
    color: white;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 24px;
    cursor: pointer;
}

.navbar.scrolled .nav-toggle {
    color: var(--text-dark);
}

/* ==========================================
   英雄区
   ========================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    background: var(--gradient-hero);
}

.hero-bg {
    position: absolute;
    inset: 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='0.05'%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: 0.3;
}

.hero-particles {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 20% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
                radial-gradient(circle at 80% 50%, rgba(255,255,255,0.1) 0%, transparent 50%);
}

.hero .container {
    position: relative;
    z-index: 2;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    padding: 120px 0 80px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    padding: 8px 20px;
    border-radius: 50px;
    color: white;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 24px;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-badge i {
    color: var(--accent-color);
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    color: white;
    line-height: 1.2;
    margin-bottom: 24px;
    letter-spacing: -0.02em;
}

.hero-title .highlight {
    background: linear-gradient(120deg, #ffd89b 0%, #f6d365 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.8;
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

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

.btn-primary,
.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 15px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(255, 255, 255, 0.3);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    padding: 40px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

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

.stat-number {
    display: block;
    font-size: 42px;
    font-weight: 700;
    color: white;
    line-height: 1;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 500;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    color: rgba(255, 255, 255, 0.6);
    font-size: 24px;
    animation: bounce 2s infinite;
}

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

/* ==========================================
   通用区块样式
   ========================================== */
section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
}

.section-tag {
    display: inline-block;
    background: var(--gradient-primary);
    color: white;
    padding: 6px 16px;
    border-radius: 50px;
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
}

.section-title {
    font-size: 40px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 16px;
    line-height: 1.3;
}

.section-desc {
    font-size: 17px;
    color: var(--text-light);
    line-height: 1.8;
}

/* ==========================================
   服务区块
   ========================================== */
.services {
    background: var(--bg-light);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.service-card {
    background: white;
    padding: 40px 32px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform 0.3s;
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.service-card:hover::before {
    transform: scaleX(1);
}

.service-card.featured {
    background: var(--gradient-primary);
    color: white;
}

.service-card.featured h3,
.service-card.featured p {
    color: white;
}

.service-card.featured .service-tags span {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.service-icon {
    width: 70px;
    height: 70px;
    border-radius: 16px;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    transition: var(--transition);
}

.service-icon i {
    font-size: 28px;
    color: var(--primary-color);
}

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

.service-card.featured .service-icon {
    background: rgba(255, 255, 255, 0.15);
}

.service-card.featured .service-icon i {
    color: white;
}

.service-card h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.service-card p {
    font-size: 15px;
    color: var(--text-gray);
    line-height: 1.7;
    margin-bottom: 20px;
}

.service-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.service-tags span {
    background: rgba(102, 126, 234, 0.08);
    color: var(--primary-color);
    padding: 4px 12px;
    border-radius: 50px;
    font-size: 12px;
    font-weight: 500;
}

/* ==========================================
   关于我们
   ========================================== */
.about {
    background: white;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.about-text .section-tag {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.about-text h2 {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 24px;
}

.about-text p {
    font-size: 16px;
    color: var(--text-gray);
    line-height: 1.9;
    margin-bottom: 20px;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-top: 32px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 15px;
    color: var(--text-dark);
}

.feature-item i {
    color: #48bb78;
    font-size: 18px;
}

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

.visual-card {
    background: var(--gradient-card);
    padding: 32px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid rgba(0, 0, 0, 0.03);
}

.visual-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-lg);
}

.visual-icon {
    width: 56px;
    height: 56px;
    border-radius: 12px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
}

.visual-icon i {
    font-size: 24px;
    color: white;
}

.visual-card h4 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.visual-card p {
    font-size: 14px;
    color: var(--text-light);
}

/* ==========================================
   技术栈
   ========================================== */
.tech-stack {
    background: var(--bg-light);
}

.tech-grid {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 24px;
}

.tech-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 32px 40px;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.tech-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.tech-item i {
    font-size: 48px;
    color: var(--primary-color);
}

.tech-item span {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-dark);
}

/* ==========================================
   联系方式
   ========================================== */
.contact {
    background: white;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

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

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 24px;
    background: var(--bg-light);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.contact-item:hover {
    background: white;
    box-shadow: var(--shadow-md);
}

.contact-icon {
    width: 56px;
    height: 56px;
    border-radius: 12px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-icon i {
    font-size: 22px;
    color: white;
}

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

.contact-detail p {
    font-size: 15px;
    color: var(--text-gray);
}

.contact-form {
    background: var(--bg-light);
    padding: 40px;
    border-radius: var(--border-radius);
}

.contact-form h3 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 24px;
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 14px 20px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    font-size: 15px;
    font-family: inherit;
    transition: var(--transition);
    background: white;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

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

.btn-submit {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 16px 32px;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ==========================================
   页脚
   ========================================== */
.footer {
    background: #1a1a2e;
    color: white;
    padding: 80px 0 0;
}

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

.footer-brand .brand-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-brand .brand-logo i {
    color: var(--accent-color);
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 15px;
}

.footer-links h4 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-links ul {
    list-style: none;
}

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

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--accent-color);
}

.social-links {
    display: flex;
    gap: 16px;
}

.social-links a {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 18px;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--accent-color);
    transform: translateY(-4px);
}

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

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

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

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

/* ==========================================
   动画
   ========================================== */
.animate-target {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-target.animate-in {
    opacity: 1;
    transform: translateY(0);
}

/* 延迟动画 */
.service-card:nth-child(2) { transition-delay: 0.1s; }
.service-card:nth-child(3) { transition-delay: 0.2s; }
.service-card:nth-child(4) { transition-delay: 0.3s; }
.service-card:nth-child(5) { transition-delay: 0.4s; }
.service-card:nth-child(6) { transition-delay: 0.5s; }

/* ==========================================
   响应式设计
   ========================================== */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 44px;
    }
    
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 60px;
    }
    
    .about-visual {
        order: -1;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    section {
        padding: 60px 0;
    }
    
    .nav-links {
        display: none;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-desc {
        font-size: 16px;
    }
    
    .hero-actions {
        flex-direction: column;
        gap: 12px;
    }
    
    .btn-primary,
    .btn-secondary {
        width: 100%;
        justify-content: center;
    }
    
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .stat-number {
        font-size: 32px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .about-features {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .social-links {
        justify-content: center;
    }
}