/* ===== CSS 变量 - 设计系统 ===== */
:root {
    /* 主色调 */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --primary-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    
    /* 中性色 */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* 语义色 */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* 背景色 */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    
    /* 文字色 */
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-tertiary: #6b7280;
    --text-inverse: #ffffff;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-glow: 0 0 40px rgba(37, 99, 235, 0.2);
    
    /* 圆角 */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    /* 间距 */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    
    /* 动画 */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* 字体 - 使用系统字体栈 */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', monospace;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

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

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

ul, ol {
    list-style: none;
}

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

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

/* ===== 工具类 ===== */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.section {
    padding: var(--space-20) 0;
}

.section-bg {
    background: var(--bg-secondary);
}

.highlight {
    /* 删除渐变效果，使用默认文字颜色 */
}

/* ===== 按钮 ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-size: 0.938rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn .icon {
    width: 1.25rem;
    height: 1.25rem;
}

.btn-primary {
    background: var(--primary-gradient);
    color: var(--text-inverse);
    box-shadow: var(--shadow-md), 0 0 20px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 30px rgba(37, 99, 235, 0.4);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--gray-300);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.btn-white {
    background: rgba(255, 255, 255, 0.95);
    color: var(--primary);
    backdrop-filter: blur(10px);
}

.btn-white:hover {
    background: #fff;
    transform: translateY(-2px);
}

.btn-lg {
    padding: var(--space-4) var(--space-8);
    font-size: 1rem;
}

/* ===== 头部导航 ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: var(--space-4) 0;
    transition: all var(--transition-base);
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-md);
    padding: var(--space-3) 0;
}

.header-content {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.logo {
    display: flex;
    align-items: center;
}

.logo-img {
    height: 40px;
    width: auto;
}

.nav {
    display: flex;
    gap: var(--space-2);
    margin-left: auto;
}

.nav-link {
    padding: var(--space-2) var(--space-4);
    font-size: 0.938rem;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
    background: var(--gray-100);
}



.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--space-2);
}

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

/* ===== Hero 区域 ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: var(--space-20) 0;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: -1;
}

.hero-gradient {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(37, 99, 235, 0.05) 0%, rgba(255, 255, 255, 0) 100%);
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(37, 99, 235, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37, 99, 235, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-16);
    align-items: center;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--space-6);
    color: var(--text-primary);
}

.hero-title .highlight {
    display: block;
    margin-top: var(--space-2);
}

.hero-desc {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-8);
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: var(--space-4);
    flex-wrap: wrap;
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-card {
    width: 100%;
    max-width: 480px;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl), var(--shadow-glow);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.5);
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.card-header {
    display: flex;
    gap: var(--space-2);
    padding: var(--space-4);
    background: var(--gray-100);
    border-bottom: 1px solid var(--gray-200);
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dot.red { background: #ef4444; }
.dot.yellow { background: #f59e0b; }
.dot.green { background: #10b981; }

.card-body {
    padding: var(--space-6);
}

.chat-demo {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.message {
    display: flex;
    gap: var(--space-3);
    align-items: flex-start;
}

.message.customer {
    flex-direction: row;
}

.message.agent {
    flex-direction: row-reverse;
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--primary-gradient);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
    flex-shrink: 0;
}

.agent-avatar {
    background: linear-gradient(135deg, #7c3aed 0%, #2563eb 100%);
}

.bubble {
    max-width: 280px;
    padding: var(--space-3) var(--space-4);
    background: var(--gray-100);
    border-radius: var(--radius-xl);
    font-size: 0.938rem;
    line-height: 1.5;
}

.message.agent .bubble {
    background: var(--primary);
    color: white;
}

/* 视频通话演示 */
.video-call-demo {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.call-participant {
    aspect-ratio: 9/16;
    background: linear-gradient(135deg, #1e3a5f 0%, #0f2744 100%);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.call-participant.remote {
    min-height: 280px;
}

.participant-avatar {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-full);
    background: var(--primary-gradient);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--space-4);
}

.participant-name {
    color: white;
    font-size: 1.125rem;
    font-weight: 600;
}

.call-controls {
    display: flex;
    justify-content: center;
    gap: var(--space-4);
    padding: var(--space-4);
}

.control-btn {
    width: 50px;
    height: 50px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.control-btn svg {
    width: 24px;
    height: 24px;
}

.control-btn.mute {
    background: var(--gray-200);
    color: var(--text-primary);
}

.control-btn.mute:hover {
    background: var(--gray-300);
}

.control-btn.end {
    background: #ef4444;
    color: white;
}

.control-btn.end:hover {
    background: #dc2626;
}

.control-btn.video {
    background: var(--gray-200);
    color: var(--text-primary);
}

.control-btn.video:hover {
    background: var(--gray-300);
}

/* ===== 数据统计 ===== */
.stats {
    padding: var(--space-16) 0;
    background: var(--bg-secondary);
    border-top: 1px solid var(--gray-200);
    border-bottom: 1px solid var(--gray-200);
}

.stats-header {
    text-align: center;
    margin-bottom: var(--space-12);
}

.stats-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: var(--space-4);
}

.stats-header p {
    color: var(--text-secondary);
    font-size: 1.125rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-8);
}

.stat-card {
    text-align: center;
    padding: var(--space-8);
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

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

.stat-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--space-4);
    color: var(--primary);
}

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

.stat-value {
    font-size: 3.5rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-2);
}

.stat-label {
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 500;
}

/* ===== 产品展示 ===== */
.products {
    background: var(--bg-primary);
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-16);
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--space-4);
}

.section-header p {
    font-size: 1.25rem;
    color: var(--text-secondary);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-8);
}

.product-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

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

.product-image {
    position: relative;
    aspect-ratio: 16/10;
    overflow: hidden;
    background: var(--gray-100);
}

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

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

.product-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-base);
}

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

.product-info {
    padding: var(--space-6);
}

.product-info h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-2);
}

.product-info p {
    color: var(--text-secondary);
    font-size: 0.938rem;
}

/* ===== 渠道展示 ===== */
.channels {
    background: var(--bg-secondary);
}

.channels-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-6);
}

.channel-card {
    background: var(--bg-primary);
    padding: var(--space-8);
    border-radius: var(--radius-xl);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

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

.channel-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--space-4);
    color: var(--primary);
}

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

.channel-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--space-2);
}

.channel-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ===== CTA 区域 ===== */
.cta {
    padding: var(--space-20) 0;
    background: var(--primary-gradient);
}

.cta-content {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.cta-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: var(--space-4);
}

.cta-content p {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--space-8);
}

/* ===== 页脚 ===== */
.footer {
    background: var(--gray-900);
    color: var(--gray-300);
    padding: var(--space-16) 0 var(--space-8);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--space-16);
    margin-bottom: var(--space-12);
}

.footer-brand .logo-img {
    height: 36px;
    margin-bottom: var(--space-4);
    filter: brightness(0) invert(1);
}

.footer-brand p:first-of-type {
    font-size: 1rem;
    font-weight: 600;
    color: white;
    margin-bottom: var(--space-2);
}

.footer-brand p:last-of-type {
    font-size: 0.875rem;
    line-height: 1.8;
    color: var(--gray-400);
}

.footer-col h4 {
    color: white;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-4);
}

.footer-col ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer-col a {
    font-size: 0.938rem;
    transition: color var(--transition-fast);
}

.footer-col a:hover {
    color: white;
}

.contact-list a {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.icon-sm {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    opacity: 0.7;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--space-8);
    border-top: 1px solid var(--gray-800);
    flex-wrap: wrap;
    gap: var(--space-4);
}

.footer-bottom p:first-child {
    margin-right: auto;
}

.footer-bottom p:last-child {
    margin-left: auto;
}

.footer-bottom p {
    font-size: 0.875rem;
}

.footer-bottom a {
    color: var(--gray-400);
}

.footer-bottom a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: var(--space-4);
}

.social-links a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-800);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.social-links a:hover {
    background: var(--primary);
    transform: translateY(-2px);
}

.social-links .icon {
    width: 20px;
    height: 20px;
}

/* ===== 返回顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: var(--space-8);
    right: var(--space-8);
    width: 50px;
    height: 50px;
    background: var(--primary-gradient);
    color: white;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

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

/* ===== 动画 ===== */
[data-aos] {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-aos].aos-animate {
    opacity: 1;
    transform: translateY(0);
}

[data-aos-delay="100"] { transition-delay: 0.1s; }
[data-aos-delay="200"] { transition-delay: 0.2s; }
[data-aos-delay="300"] { transition-delay: 0.3s; }
[data-aos-delay="400"] { transition-delay: 0.4s; }

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-visual {
        order: -1;
    }
    
    .hero-cta {
        justify-content: center;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .channels-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--bg-primary);
        flex-direction: column;
        padding: var(--space-20) var(--space-6);
        box-shadow: var(--shadow-xl);
        transition: right var(--transition-base);
        margin-left: 0;
    }
    
    .nav.active {
        right: 0;
    }
    
    .nav-link {
        padding: var(--space-4);
        font-size: 1rem;
    }
    
    .mobile-toggle {
        display: flex;
        margin-left: auto;
    }
    
    .cta-btn {
        display: none;
    }
    
    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .channels-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .stat-value {
        font-size: 2.5rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-desc {
        font-size: 1rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .section-header h2 {
        font-size: 1.75rem;
    }
    
    .cta-content h2 {
        font-size: 1.75rem;
    }
}