/* ============================================
   智能销售助手网站样式表
   设计风格：科技前沿、浅色模式、现代简约
   ============================================ */

/* ============================================
   1. CSS变量定义（色彩系统）
   ============================================ */
:root {
    /* 主色调 */
    --color-primary: #2563EB;
    --color-primary-dark: #1E40AF;
    --color-primary-light: #3B82F6;
    
    /* 渐变色彩 */
    --gradient-primary: linear-gradient(135deg, #2563EB 0%, #6366F1 100%);
    --gradient-secondary: linear-gradient(135deg, #6366F1 0%, #8B5CF6 100%);
    --gradient-cta: linear-gradient(135deg, #F59E0B 0%, #EF4444 100%);
    
    /* 辅助色 */
    --color-accent: #06B6D4;
    --color-accent-light: #E0F2FE;
    
    /* 背景色 - 深色主题 */
    --color-bg: #F5F7FA;
    --color-bg-light: #EAEDF1;
    --color-bg-gray: #E1E5E9;
    
    /* 文字色 - 更有活力的配色 */
    --color-text: #111827;
    --color-text-light: #4B5563;
    --color-text-lighter: #6B7280;
    --color-text-accent: #2563EB;
    
    /* 文字渐变 */
    --gradient-text-primary: linear-gradient(135deg, #2563EB 0%, #6366F1 50%, #8B5CF6 100%);
    --gradient-text-secondary: linear-gradient(135deg, #06B6D4 0%, #3B82F6 100%);
    
    /* 边框色 - 适配深色背景 */
    --color-border: #D1D5DB;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 8px 24px rgba(0, 0, 0, 0.16);
    
    /* 间距系统（8px倍数） */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
    --spacing-2xl: 64px;
    --spacing-3xl: 96px;
    --spacing-4xl: 128px;
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* 字体 */
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    --font-family-en: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
    
    /* 过渡动画 */
    --transition-fast: 0.2s ease-out;
    --transition-base: 0.3s ease-out;
    --transition-slow: 0.6s ease-out;
}

/* ============================================
   2. 基础样式重置
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

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

/* ============================================
   全局粒子动画背景
   ============================================ */
#particleCanvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none; /* 不拦截鼠标事件，让页面元素可点击 */
    z-index: 1; /* 在背景之上，但在内容之下 */
}

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

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }
}

/* ============================================
   4. 顶部导航栏
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: var(--spacing-sm) 0;
    background-color: rgba(245, 247, 250, 0.95);
    backdrop-filter: blur(10px);
    transition: all var(--transition-base);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
    background-color: rgba(245, 247, 250, 0.98);
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Logo样式 */
.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 20px;
    font-weight: 700;
    color: #111827;
    text-decoration: none;
}

.logo-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-link {
    color: #111827;
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-fast);
}

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

/* 登录/注册按钮 */
.nav-auth {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background-color: #111827;
    transition: all var(--transition-fast);
}

/* 响应式导航 */
@media (max-width: 1024px) {
    .nav-menu {
        gap: var(--spacing-md);
    }
    
    .nav-link {
        font-size: 14px;
    }
}

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: #FFFFFF;
        padding: var(--spacing-lg);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        transition: all var(--transition-base);
        border-bottom: 1px solid var(--color-border);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
    }
    
    .nav-auth {
        gap: var(--spacing-xs);
    }
}

/* ============================================
   5. 按钮样式
   ============================================ */
.btn-primary,
.btn-secondary,
.btn-text {
    border: none;
    cursor: pointer;
    font-family: var(--font-family);
    font-weight: 600;
    transition: all var(--transition-base);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    border-radius: var(--radius-md);
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

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

.btn-text {
    background: transparent;
    color: #111827;
    padding: var(--spacing-xs) var(--spacing-sm);
}

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

/* 按钮尺寸 */
.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: 14px;
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 18px;
}

.btn-full {
    width: 100%;
}

/* ============================================
   6. Hero首屏区域
   ============================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    overflow: hidden;
    z-index: 2; /* 确保内容在粒子之上 */
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
}


.grid-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(rgba(37, 99, 235, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37, 99, 235, 0.05) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
    0% {
        transform: translate(0, 0);
    }
    100% {
        transform: translate(50px, 50px);
    }
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-4xl);
    align-items: center;
}

.hero-text {
    z-index: 1;
}

.hero-title {
    font-size: 64px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 20px;
    color: #374151;
    margin-bottom: var(--spacing-2xl);
    line-height: 1.8;
    font-weight: 400;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
}

/* 对话预览窗口 */
.hero-visual {
    position: relative;
}

.chat-preview {
    position: relative;
    animation: float 6s ease-in-out infinite;
}

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

.chat-window {
    background: #FFFFFF;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    max-width: 400px;
    margin: 0 auto;
    border: 1px solid var(--color-border);
}

.chat-header {
    background: var(--gradient-primary);
    padding: var(--spacing-md);
    color: white;
}

.chat-status {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 14px;
}

.status-dot {
    width: 8px;
    height: 8px;
    background: #10B981;
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

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

.chat-messages {
    padding: var(--spacing-md);
    min-height: 300px;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.message {
    display: flex;
    max-width: 80%;
}

.message.user {
    align-self: flex-end;
}

.message.bot {
    align-self: flex-start;
}

.message-content {
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    background: var(--color-bg-light);
}

.message.user .message-content {
    background: var(--gradient-primary);
    color: white;
}

.message.typing .message-content {
    display: flex;
    gap: 4px;
    padding: var(--spacing-sm) var(--spacing-md);
}

.message.typing span {
    width: 8px;
    height: 8px;
    background: #6B7280;
    border-radius: 50%;
    animation: typing 1.4s ease-in-out infinite;
}

.message.typing span:nth-child(2) {
    animation-delay: 0.2s;
}

.message.typing span:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typing {
    0%, 60%, 100% {
        transform: translateY(0);
    }
    30% {
        transform: translateY(-10px);
    }
}

/* 响应式Hero */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }
    
    .hero-title {
        font-size: 48px;
    }
    
    .hero-visual {
        order: -1;
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .hero-cta button {
        width: 100%;
    }
}

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

.delay-1 {
    animation-delay: 0.1s;
}

.delay-2 {
    animation-delay: 0.2s;
}

.delay-3 {
    animation-delay: 0.3s;
}

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

/* ============================================
   8. 核心价值展示区
   ============================================ */
.values,
.features,
.integration,
.stats,
.cases,
.pricing,
.cta-section,
.footer {
    position: relative;
    z-index: 2; /* 确保内容在粒子之上 */
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-2xl);
}

.value-card {
    background: #FFFFFF;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
}

.value-card:hover {
    transform: translateY(-8px) rotateY(5deg);
    box-shadow: var(--shadow-xl);
}

.value-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    color: white;
}

.value-title {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: #111827;
    background: var(--gradient-text-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.value-desc {
    color: #4B5563;
    font-size: 16px;
    line-height: 1.7;
}

@media (max-width: 768px) {
    .values-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   9. 功能特性区域
   ============================================ */
.features {
    padding: var(--spacing-4xl) 0;
}

.section-title {
    font-size: 40px;
    font-weight: 800;
    text-align: center;
    margin-bottom: var(--spacing-3xl);
    background: var(--gradient-text-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.feature-card {
    background: #FFFFFF;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

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

.feature-icon {
    width: 56px;
    height: 56px;
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-accent-light);
    border-radius: var(--radius-md);
    color: var(--color-primary);
}

.feature-title {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: #111827;
}

.feature-desc {
    color: #4B5563;
    line-height: 1.7;
}

@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 32px;
    }
}

/* ============================================
   10. 技术集成区域
   ============================================ */
.integration {
    padding: var(--spacing-4xl) 0;
    background: var(--color-bg-light);
}

.integration-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-4xl);
    align-items: center;
}

.integration-desc {
    font-size: 18px;
    color: #374151;
    margin-bottom: var(--spacing-2xl);
    line-height: 1.8;
}

.integration-features {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.integration-feature {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: #111827;
    font-weight: 500;
}

.integration-feature svg {
    color: var(--color-primary);
}

/* 代码块样式 */
.code-block {
    background: #1F2937;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: #111827;
    border-bottom: 1px solid #374151;
}

.code-title {
    color: #D1D5DB;
    font-size: 14px;
    font-weight: 500;
}

.code-copy {
    background: none;
    border: none;
    color: #D1D5DB;
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.code-copy:hover {
    background: #374151;
    color: white;
}

.code-content {
    padding: var(--spacing-xl);
    margin: 0;
    overflow-x: auto;
}

.code-content code {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
    color: #E5E7EB;
    line-height: 1.6;
}

@media (max-width: 1024px) {
    .integration-content {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   11. 数据统计区域
   ============================================ */
.stats {
    padding: var(--spacing-4xl) 0;
}

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

.stat-card {
    text-align: center;
    padding: var(--spacing-xl);
}

.stat-number {
    font-size: 56px;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

.stat-label {
    font-size: 16px;
    color: #4B5563;
    font-weight: 500;
}

@media (max-width: 768px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .stat-number {
        font-size: 40px;
    }
}

/* ============================================
   12. 客户案例区域
   ============================================ */
.cases {
    padding: var(--spacing-4xl) 0;
    background: var(--color-bg-light);
}

.cases-slider {
    overflow: hidden;
    margin-bottom: var(--spacing-xl);
}

.cases-track {
    display: flex;
    gap: var(--spacing-xl);
    transition: transform var(--transition-slow);
}

.case-card {
    flex: 0 0 calc(33.333% - 32px);
    background: #FFFFFF;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    border: 1px solid var(--color-border);
}

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

.case-logo {
    margin-bottom: var(--spacing-lg);
}

.logo-placeholder {
    font-size: 24px;
    font-weight: 700;
    color: var(--color-primary);
    padding: var(--spacing-md);
    background: var(--color-accent-light);
    border-radius: var(--radius-md);
    text-align: center;
}

.case-desc {
    color: #374151;
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
    font-style: italic;
    font-size: 15px;
}

.case-result {
    display: flex;
    gap: var(--spacing-lg);
}

.case-metric {
    display: flex;
    flex-direction: column;
}

.metric-value {
    font-size: 32px;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.metric-label {
    font-size: 14px;
    color: #4B5563;
    font-weight: 500;
}

.cases-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
}

.cases-nav-btn {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: 2px solid var(--color-border);
    background: #FFFFFF;
    color: #111827;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.cases-nav-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: scale(1.1);
}

.cases-dots {
    display: flex;
    gap: var(--spacing-xs);
}

.cases-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-border);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.cases-dot.active {
    background: var(--color-primary);
    width: 24px;
    border-radius: 4px;
}

@media (max-width: 1024px) {
    .case-card {
        flex: 0 0 calc(50% - 24px);
    }
}

@media (max-width: 768px) {
    .case-card {
        flex: 0 0 100%;
    }
}

/* ============================================
   13. 定价方案区域
   ============================================ */
.pricing {
    padding: var(--spacing-4xl) 0;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    max-width: 1100px;
    margin: 0 auto;
}

.pricing-card {
    background: #FFFFFF;
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    border: 2px solid var(--color-border);
    position: relative;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

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

.pricing-card-featured {
    border-color: var(--color-primary);
    transform: scale(1.05);
}

.pricing-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--gradient-primary);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 600;
}

.pricing-header {
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.pricing-name {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: #111827;
    background: var(--gradient-text-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.pricing-price {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
}

.price-currency {
    font-size: 24px;
    font-weight: 600;
    color: #6B7280;
}

.price-amount {
    font-size: 56px;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
    text-align: center;
}

.price-period {
    font-size: 16px;
    color: #6B7280;
    margin-top: 4px;
}

.pricing-features {
    list-style: none;
    margin-bottom: var(--spacing-xl);
}

.pricing-features li {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    color: #111827;
}

.pricing-features li svg {
    color: var(--color-primary);
    flex-shrink: 0;
}

@media (max-width: 1024px) {
    .pricing-grid {
        grid-template-columns: 1fr;
    }
    
    .pricing-card-featured {
        transform: scale(1);
    }
}

/* ============================================
   14. CTA行动号召区域
   ============================================ */
.cta-section {
    padding: var(--spacing-4xl) 0;
    background: var(--gradient-primary);
    color: white;
}

.cta-content {
    text-align: center;
}

.cta-title {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: var(--spacing-md);
}

.cta-subtitle {
    font-size: 20px;
    margin-bottom: var(--spacing-2xl);
    opacity: 0.9;
}

.cta-section .btn-primary {
    background: white;
    color: var(--color-primary);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.cta-section .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

@media (max-width: 768px) {
    .cta-title {
        font-size: 36px;
    }
    
    .cta-subtitle {
        font-size: 18px;
    }
}

/* ============================================
   15. 页脚
   ============================================ */
.footer {
    padding: var(--spacing-4xl) 0 var(--spacing-xl);
    background: var(--color-bg-light);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 18px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: #111827;
}

.footer-desc {
    color: #4B5563;
    line-height: 1.7;
}

.footer-title {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: #111827;
}

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

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: #4B5563;
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

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

.footer-copyright {
    color: #6B7280;
    font-size: 14px;
}

.footer-social {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: #FFFFFF;
    color: #6B7280;
    transition: all var(--transition-fast);
    border: 1px solid var(--color-border);
}

.social-link:hover {
    background: var(--color-primary);
    color: white;
    transform: translateY(-2px);
}

@media (max-width: 1024px) {
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}

/* ============================================
   16. 登录/注册弹窗
   ============================================ */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: #FFFFFF;
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    max-width: 440px;
    width: 100%;
    box-shadow: var(--shadow-xl);
    animation: modalSlideIn 0.3s ease-out;
    z-index: 1;
    border: 1px solid var(--color-border);
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: scale(0.9) translateY(-20px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: none;
    border: none;
    cursor: pointer;
    color: #6B7280;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background: var(--color-bg-light);
    color: #111827;
}

.auth-tabs {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--color-border);
}

.auth-tab {
    background: none;
    border: none;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 16px;
    font-weight: 600;
    color: #6B7280;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    transition: all var(--transition-fast);
}

.auth-tab.active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.auth-form.hidden {
    display: none;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-size: 14px;
    font-weight: 600;
    color: #111827;
}

.form-group input {
    padding: var(--spacing-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 16px;
    font-family: var(--font-family);
    transition: all var(--transition-fast);
}

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

.verify-code-group {
    display: flex;
    gap: var(--spacing-sm);
}

.verify-code-group input {
    flex: 1;
}

.btn-code {
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-bg-light);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 14px;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

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

.form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 14px;
    color: #4B5563;
    cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.forgot-password {
    font-size: 14px;
    color: var(--color-primary);
    text-decoration: none;
}

.forgot-password:hover {
    text-decoration: underline;
}

/* ============================================
   18. 跳转提示弹窗
   ============================================ */
.redirect-content {
    text-align: center;
    padding: var(--spacing-md) 0;
}

.redirect-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    color: white;
}

.redirect-title {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: #111827;
}

.redirect-message {
    font-size: 16px;
    color: #4B5563;
    margin-bottom: var(--spacing-xl);
    line-height: 1.6;
}

.redirect-url {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--color-bg-light);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.url-label {
    font-size: 14px;
    color: #6B7280;
    font-weight: 500;
}

.url-text {
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
    color: #111827;
    background: white;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
    flex: 1;
    min-width: 200px;
    word-break: break-all;
}

.btn-copy-url {
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: var(--spacing-xs);
    cursor: pointer;
    color: #6B7280;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

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

.redirect-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

.redirect-actions .btn-primary,
.redirect-actions .btn-secondary {
    flex: 1;
    max-width: 200px;
}

@media (max-width: 768px) {
    .redirect-url {
        flex-direction: column;
        align-items: stretch;
    }
    
    .url-text {
        min-width: 100%;
    }
    
    .redirect-actions {
        flex-direction: column;
    }
    
    .redirect-actions .btn-primary,
    .redirect-actions .btn-secondary {
        max-width: 100%;
    }
}

/* ============================================
   19. 工具类
   ============================================ */
.hidden {
    display: none !important;
}

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

/* ============================================
   18. 响应式工具类
   ============================================ */
@media (max-width: 768px) {
    .mobile-hidden {
        display: none !important;
    }
}