/* ============================================
   快连 Kuailian v5 - 赛博霓虹风格
   Cyberpunk Neon Aesthetic
   ============================================ */

/* CSS 变量定义 - 赛博霓虹主题 */
:root {
    /* 霓虹色彩系统 */
    --neon-cyan: #00f5ff;
    --neon-cyan-glow: rgba(0, 245, 255, 0.5);
    --neon-pink: #ff00ff;
    --neon-pink-glow: rgba(255, 0, 255, 0.5);
    --neon-purple: #b829dd;
    --neon-purple-glow: rgba(184, 41, 221, 0.5);
    --neon-green: #39ff14;
    --neon-green-glow: rgba(57, 255, 20, 0.5);
    
    /* 深色背景色阶 */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a25;
    --bg-card: #151520;
    --bg-glass: rgba(21, 21, 32, 0.8);
    
    /* 文字色彩 */
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --text-muted: #606070;
    --text-accent: var(--neon-cyan);
    
    /* 边框与线条 */
    --border-subtle: rgba(255, 255, 255, 0.05);
    --border-neon: rgba(0, 245, 255, 0.3);
    --border-glow: 0 0 20px var(--neon-cyan-glow);
    
    /* 阴影系统 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
    --shadow-neon: 0 0 30px var(--neon-cyan-glow), 0 0 60px var(--neon-purple-glow);
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 30px;
    --radius-full: 9999px;
    
    /* 间距 */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;
    
    /* 字体 - 使用系统字体栈，无需外部加载 */
    --font-display: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    
    /* 过渡 */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

/* 动态背景网格 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(rgba(0, 245, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 245, 255, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
    z-index: -1;
}

/* 背景光晕效果 */
body::after {
    content: '';
    position: fixed;
    top: -50%;
    left: -50%;
    right: -50%;
    bottom: -50%;
    background: 
        radial-gradient(ellipse at 20% 20%, rgba(0, 245, 255, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(255, 0, 255, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(184, 41, 221, 0.05) 0%, transparent 60%);
    pointer-events: none;
    z-index: -1;
    animation: bgPulse 10s ease-in-out infinite;
}

@keyframes bgPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

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

ul {
    list-style: none;
}

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

/* ============================================
   布局容器
   ============================================ */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.section {
    padding: var(--space-4xl) 0;
    position: relative;
}

.section-alt {
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

/* ============================================
   导航栏 - 赛博风格
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-subtle);
}

.navbar::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, 
        transparent 0%, 
        var(--neon-cyan) 20%, 
        var(--neon-purple) 50%, 
        var(--neon-cyan) 80%, 
        transparent 100%
    );
    opacity: 0.5;
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 2px;
}

.logo-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: 0 0 20px var(--neon-cyan-glow);
    animation: logoPulse 2s ease-in-out infinite;
}

.logo-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

@keyframes logoPulse {
    0%, 100% { box-shadow: 0 0 20px var(--neon-cyan-glow); }
    50% { box-shadow: 0 0 30px var(--neon-cyan-glow), 0 0 50px var(--neon-purple-glow); }
}

.logo span {
    background: linear-gradient(135deg, var(--text-primary), var(--neon-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 导航菜单 */
.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: var(--space-sm) 0;
    position: relative;
    transition: all var(--transition-fast);
    letter-spacing: 0.5px;
}

.nav-link:hover,
.nav-link.active {
    color: var(--neon-cyan);
    text-shadow: 0 0 10px var(--neon-cyan-glow);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--neon-cyan), var(--neon-purple));
    transition: width var(--transition-base);
    box-shadow: 0 0 10px var(--neon-cyan-glow);
}

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

/* CTA按钮 */
.nav-cta {
    background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
    color: var(--bg-primary) !important;
    padding: var(--space-sm) var(--space-lg) !important;
    border-radius: var(--radius-full);
    font-weight: 600;
    box-shadow: 0 4px 15px var(--neon-cyan-glow);
    transition: all var(--transition-base);
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px var(--neon-cyan-glow), 0 0 40px var(--neon-purple-glow);
}

.nav-cta::after {
    display: none !important;
}

/* 移动端菜单按钮 */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
    padding: var(--space-sm);
    z-index: 1001;
}

.menu-toggle span {
    width: 28px;
    height: 2px;
    background: linear-gradient(90deg, var(--neon-cyan), var(--neon-purple));
    transition: all var(--transition-fast);
    box-shadow: 0 0 5px var(--neon-cyan-glow);
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ============================================
   按钮组件 - 霓虹风格
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: var(--font-body);
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
    color: var(--bg-primary);
    box-shadow: 0 4px 20px var(--neon-cyan-glow);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px var(--neon-cyan-glow), 0 0 50px var(--neon-purple-glow);
}

.btn-secondary {
    background: transparent;
    color: var(--neon-cyan);
    border: 2px solid var(--neon-cyan);
    box-shadow: 0 0 10px var(--neon-cyan-glow), inset 0 0 10px var(--neon-cyan-glow);
}

.btn-secondary:hover {
    background: rgba(0, 245, 255, 0.1);
    box-shadow: 0 0 20px var(--neon-cyan-glow), inset 0 0 20px var(--neon-cyan-glow);
}

.btn-accent {
    background: linear-gradient(135deg, var(--neon-pink), var(--neon-purple));
    color: var(--text-primary);
    box-shadow: 0 4px 20px var(--neon-pink-glow);
}

.btn-accent:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px var(--neon-pink-glow), 0 0 50px var(--neon-purple-glow);
}

.btn-lg {
    padding: var(--space-lg) var(--space-2xl);
    font-size: 1.1rem;
}

.btn-sm {
    padding: var(--space-sm) var(--space-md);
    font-size: 0.875rem;
}

/* ============================================
   卡片组件 - 玻璃拟态
   ============================================ */
.card {
    background: var(--bg-glass);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    border: 1px solid var(--border-subtle);
    backdrop-filter: blur(10px);
    transition: all var(--transition-base);
    position: relative;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--neon-cyan), transparent);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--border-neon);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4), 0 0 30px var(--neon-cyan-glow);
}

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

.card-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, rgba(0, 245, 255, 0.1), rgba(184, 41, 221, 0.1));
    border: 1px solid var(--border-neon);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    margin-bottom: var(--space-lg);
    box-shadow: 0 0 20px var(--neon-cyan-glow);
}

.card-title {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
    color: var(--text-primary);
}

.card-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   标签组件
   ============================================ */
.tag {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    letter-spacing: 0.5px;
}

.tag-cyan {
    background: rgba(0, 245, 255, 0.15);
    color: var(--neon-cyan);
    border: 1px solid var(--neon-cyan);
    box-shadow: 0 0 10px var(--neon-cyan-glow);
}

.tag-pink {
    background: rgba(255, 0, 255, 0.15);
    color: var(--neon-pink);
    border: 1px solid var(--neon-pink);
    box-shadow: 0 0 10px var(--neon-pink-glow);
}

.tag-purple {
    background: rgba(184, 41, 221, 0.15);
    color: var(--neon-purple);
    border: 1px solid var(--neon-purple);
    box-shadow: 0 0 10px var(--neon-purple-glow);
}

.tag-green {
    background: rgba(57, 255, 20, 0.15);
    color: var(--neon-green);
    border: 1px solid var(--neon-green);
    box-shadow: 0 0 10px var(--neon-green-glow);
}

/* ============================================
   页面标题区
   ============================================ */
.page-header {
    padding: calc(80px + var(--space-4xl)) 0 var(--space-3xl);
    text-align: center;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    position: relative;
}

.page-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(ellipse at 50% 0%, rgba(0, 245, 255, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.page-title {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
    text-shadow: 0 0 30px var(--neon-cyan-glow);
    letter-spacing: 2px;
}

.page-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   信任标识
   ============================================ */
.trust-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: rgba(0, 245, 255, 0.1);
    border: 1px solid var(--neon-cyan);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--neon-cyan);
    box-shadow: 0 0 15px var(--neon-cyan-glow);
}

.trust-badge::before {
    content: '◆';
    color: var(--neon-cyan);
    animation: badgePulse 1.5s ease-in-out infinite;
}

@keyframes badgePulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* ============================================
   FAQ 手风琴
   ============================================ */
.faq-item {
    background: var(--bg-glass);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-md);
    overflow: hidden;
    backdrop-filter: blur(10px);
    transition: all var(--transition-base);
}

.faq-item:hover {
    border-color: var(--border-neon);
}

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-lg);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.faq-question:hover {
    background: rgba(0, 245, 255, 0.05);
}

.faq-question h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.faq-icon {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-base);
    color: var(--neon-cyan);
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 var(--space-lg) var(--space-lg);
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ============================================
   Footer - 赛博风格
   ============================================ */
.footer {
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: var(--space-3xl) 0 var(--space-xl);
    border-top: 1px solid var(--border-subtle);
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, 
        transparent 0%, 
        var(--neon-cyan) 30%, 
        var(--neon-purple) 70%, 
        transparent 100%
    );
    opacity: 0.5;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

.footer-brand {
    max-width: 300px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

.footer-logo span:first-child {
    background: linear-gradient(135deg, var(--neon-cyan), var(--neon-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.footer-title {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--neon-cyan);
    margin-bottom: var(--space-lg);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer-links a {
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    position: relative;
    padding-left: 0;
}

.footer-links a::before {
    content: '>';
    position: absolute;
    left: -15px;
    opacity: 0;
    color: var(--neon-cyan);
    transition: all var(--transition-fast);
}

.footer-links a:hover {
    color: var(--neon-cyan);
    padding-left: 15px;
    text-shadow: 0 0 10px var(--neon-cyan-glow);
}

.footer-links a:hover::before {
    opacity: 1;
    left: 0;
}

.footer-bottom {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-xl) 0;
    border-top: 1px solid var(--border-subtle);
}

.footer-copyright {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-align: center;
}

/* ============================================
   响应式设计
   ============================================ */
@media (max-width: 1024px) {
    .section {
        padding: var(--space-3xl) 0;
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .page-title {
        font-size: 2.5rem;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        background: rgba(10, 10, 15, 0.98);
        flex-direction: column;
        padding: var(--space-xl);
        gap: var(--space-md);
        border-bottom: 1px solid var(--border-neon);
        transform: translateY(-150%);
        opacity: 0;
        pointer-events: none;
        transition: all var(--transition-base);
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .page-title {
        font-size: 2rem;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--space-md);
        text-align: center;
    }
}

@media (max-width: 480px) {
    :root {
        --space-4xl: 4rem;
        --space-3xl: 3rem;
    }
    
    .container {
        padding: 0 var(--space-md);
    }
    
    .page-title {
        font-size: 1.75rem;
    }
    
    .btn-lg {
        padding: var(--space-md) var(--space-xl);
        font-size: 1rem;
    }
    
    .logo {
        font-size: 1.4rem;
    }
    
    .logo-icon {
        width: 38px;
        height: 38px;
        font-size: 1rem;
    }
}

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

@keyframes neonFlicker {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

.animate-fadeInUp {
    animation: fadeInUp 0.6s ease forwards;
}

/* 滚动显示动画 */
.js .reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 霓虹文字效果 */
.neon-text {
    color: var(--neon-cyan);
    text-shadow: 
        0 0 5px var(--neon-cyan),
        0 0 10px var(--neon-cyan),
        0 0 20px var(--neon-cyan-glow),
        0 0 40px var(--neon-cyan-glow);
}

.neon-text-pink {
    color: var(--neon-pink);
    text-shadow: 
        0 0 5px var(--neon-pink),
        0 0 10px var(--neon-pink),
        0 0 20px var(--neon-pink-glow),
        0 0 40px var(--neon-pink-glow);
}

/* 渐变文字 */
.gradient-text {
    background: linear-gradient(135deg, var(--neon-cyan), var(--neon-pink), var(--neon-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    background-size: 200% 200%;
    animation: gradientShift 3s ease infinite;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}