/* CSS变量定义 - 支持主题切换 */
:root {
    /* 深色主题变量 */
    --bg-primary: #0a0a0a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #1a1a1a;
    --bg-card: linear-gradient(145deg, #1a1a1a, #2d2d2d);
    --text-primary: #f8fafc;
    --text-secondary: #e2e8f0;
    --text-muted: #94a3b8;
    --text-muted-dark: #64748b;
    --accent-primary: #3b82f6;
    --accent-secondary: #06b6d4;
    --accent-tertiary: #8b5cf6;
    --border-color: rgba(59, 130, 246, 0.1);
    --shadow-light: rgba(0, 0, 0, 0.3);
    --shadow-heavy: rgba(0, 0, 0, 0.5);
    --glow-color: rgba(59, 130, 246, 0.3);
    
    /* 版块背景色 */
    --section-bg: #181c24;
    --card-bg: #23283a;
    --card-text: #f8fafc;
    --card-text-muted: #bfc8e2;
}

/* 浅色主题变量 */
[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-card: linear-gradient(145deg, #ffffff, #f8fafc);
    --text-primary: #1e293b;
    --text-secondary: #334155;
    --text-muted: #64748b;
    --text-muted-dark: #94a3b8;
    --accent-primary: #3b82f6;
    --accent-secondary: #06b6d4;
    --accent-tertiary: #8b5cf6;
    --border-color: rgba(59, 130, 246, 0.2);
    --shadow-light: rgba(0, 0, 0, 0.1);
    --shadow-heavy: rgba(0, 0, 0, 0.15);
    --glow-color: rgba(59, 130, 246, 0.2);
    
    /* 版块背景色 */
    --section-bg: #f7f9fb;
    --card-bg: #ffffff;
    --card-text: #23283a;
    --card-text-muted: #5a627a;
}

/* 重置和基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    /* 防止移动端缩放 */
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
    /* 平滑滚动 */
    scroll-behavior: smooth;
    /* 支持安全区域 (iPhone X 及以上刘海屏) */
    --safe-area-top: env(safe-area-inset-top, 0px);
    --safe-area-bottom: env(safe-area-inset-bottom, 0px);
    --safe-area-left: env(safe-area-inset-left, 0px);
    --safe-area-right: env(safe-area-inset-right, 0px);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-secondary);
    overflow-x: hidden;
    background: var(--bg-primary);
    transition: all 0.3s ease;
    /* 移动端优化 */
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    /* 防止移动端滚动卡顿 */
    -webkit-overflow-scrolling: touch;
    /* 安全区域适配 */
    padding-top: var(--safe-area-top);
    padding-bottom: var(--safe-area-bottom);
    padding-left: var(--safe-area-left);
    padding-right: var(--safe-area-right);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 1000;
    padding: 1rem 0;
    transition: all 0.3s ease;
    border-bottom: 1px solid var(--border-color);
}

[data-theme="light"] .navbar {
    background: rgba(255, 255, 255, 0.95);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
}

.nav-logo i {
    margin-right: 0.5rem;
    font-size: 1.8rem;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-logo .logo-icon {
    margin-right: 0.5rem;
    flex-shrink: 0;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    /* 移动端触摸优化 */
    padding: 0.5rem 0;
    min-height: 44px;
    display: flex;
    align-items: center;
}

.nav-menu a:hover {
    color: var(--accent-primary);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    transition: width 0.3s ease;
}

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

.nav-buttons {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* 联系邮箱样式 */
.contact-email {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(59, 130, 246, 0.1);
    border-radius: 8px;
    border: 1px solid rgba(59, 130, 246, 0.2);
    transition: all 0.3s ease;
}

.contact-email:hover {
    background: rgba(59, 130, 246, 0.2);
    transform: translateY(-1px);
}

.contact-email i {
    color: var(--accent-primary);
    font-size: 0.9rem;
}

.contact-email a {
    color: var(--accent-primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
}

/* 主题切换按钮 */
.theme-toggle {
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.2);
    color: var(--accent-primary);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    /* 移动端触摸优化 */
    min-width: 44px;
    min-height: 44px;
}

.theme-toggle:hover {
    background: rgba(59, 130, 246, 0.2);
    transform: scale(1.1);
}

/* 语言切换按钮 */
.lang-toggle {
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.2);
    color: var(--accent-primary);
    padding: 0.5rem 0.75rem;
    border-radius: 20px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    font-weight: 500;
    /* 移动端触摸优化 */
    min-height: 44px;
    min-width: 60px;
    justify-content: center;
}

.lang-toggle:hover {
    background: rgba(59, 130, 246, 0.2);
    transform: translateY(-1px);
}

.lang-text {
    font-size: 0.8rem;
    font-weight: 600;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    /* 移动端触摸优化 */
    padding: 8px;
    min-width: 44px;
    min-height: 44px;
    justify-content: center;
    align-items: center;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--accent-primary);
    margin: 3px 0;
    transition: 0.3s;
    border-radius: 2px;
}

/* 按钮样式 */
.btn-primary, .btn-secondary, .btn-outline {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    position: relative;
    overflow: hidden;
    /* 移动端触摸优化 */
    min-height: 44px;
    min-width: 44px;
    justify-content: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    box-shadow: 0 4px 15px var(--glow-color);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px var(--glow-color);
}

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

.btn-secondary {
    background: rgba(59, 130, 246, 0.1);
    color: var(--accent-primary);
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.btn-secondary:hover {
    background: rgba(59, 130, 246, 0.2);
    border-color: var(--accent-primary);
}

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

.btn-outline:hover {
    background: var(--accent-primary);
    color: white;
    box-shadow: 0 4px 15px var(--glow-color);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* 主页横幅 */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 50%, var(--bg-tertiary) 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 80%, rgba(59, 130, 246, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(6, 182, 212, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(139, 92, 246, 0.05) 0%, transparent 50%);
    pointer-events: none;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.gradient-text {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary), var(--accent-tertiary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: gradientShift 3s ease-in-out infinite;
}

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

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
}

.hero-stats {
    display: flex;
    gap: 2rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-primary);
    text-shadow: 0 0 20px var(--glow-color);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-muted-dark);
}

/* 产品展示区域 */
.product-showcase {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

/* 手机模拟器 */
.phone-mockup {
    background: linear-gradient(145deg, #1a1a1a, #2d2d2d);
    border-radius: 30px;
    padding: 8px;
    box-shadow: 
        0 20px 40px var(--shadow-heavy),
        0 0 0 1px rgba(59, 130, 246, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    max-width: 300px;
    margin: 0 auto;
    position: relative;
    transition: all 0.3s ease;
}

.phone-mockup:hover {
    transform: translateY(-5px);
    box-shadow: 
        0 30px 60px var(--shadow-heavy),
        0 0 0 1px rgba(59, 130, 246, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

[data-theme="light"] .phone-mockup {
    background: linear-gradient(145deg, #f8fafc, #e2e8f0);
    box-shadow: 
        0 20px 40px var(--shadow-heavy),
        0 0 0 1px rgba(59, 130, 246, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

/* 功能亮点 */
.feature-highlights {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
    margin-top: 1rem;
}

.highlight-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background: rgba(59, 130, 246, 0.1);
    border-radius: 25px;
    border: 1px solid rgba(59, 130, 246, 0.2);
    color: var(--accent-primary);
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.highlight-item:hover {
    background: rgba(59, 130, 246, 0.2);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--glow-color);
}

.highlight-item i {
    font-size: 1rem;
}

.phone-mockup::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(45deg, var(--accent-primary), var(--accent-secondary), var(--accent-tertiary));
    border-radius: 32px;
    z-index: -1;
    opacity: 0.3;
    animation: borderGlow 3s ease-in-out infinite;
}

@keyframes borderGlow {
    0%, 100% {
        opacity: 0.3;
    }
    50% {
        opacity: 0.6;
    }
}

.phone-screen {
    background: var(--bg-secondary);
    border-radius: 22px;
    overflow: hidden;
    height: 500px;
    display: flex;
    flex-direction: column;
}

.chat-header {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.chat-avatar {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.chat-info {
    flex: 1;
}

.chat-info h4 {
    margin: 0;
    font-size: 1rem;
}

.status {
    font-size: 0.8rem;
    opacity: 0.8;
}

.chat-actions {
    display: flex;
    gap: 1rem;
}

.chat-actions i {
    cursor: pointer;
    transition: opacity 0.3s ease;
    /* 移动端触摸优化 */
    padding: 8px;
    min-width: 32px;
    min-height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.chat-actions i:hover {
    opacity: 0.7;
}

.chat-messages {
    flex: 1;
    padding: 1rem;
    overflow-y: auto;
    background: var(--bg-tertiary);
}

.message {
    margin-bottom: 1rem;
    display: flex;
    flex-direction: column;
}

.message.received {
    align-items: flex-start;
}

.message.sent {
    align-items: flex-end;
}

.message-content {
    max-width: 80%;
    padding: 0.75rem 1rem;
    border-radius: 18px;
    font-size: 0.9rem;
    line-height: 1.4;
}

.message.received .message-content {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    box-shadow: 0 1px 3px var(--shadow-light);
}

.message.sent .message-content {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
}

.message-time {
    font-size: 0.7rem;
    color: var(--text-muted-dark);
    margin-top: 0.25rem;
}

.chat-input {
    background: var(--bg-secondary);
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border-top: 1px solid var(--border-color);
}

.chat-input input {
    flex: 1;
    border: none;
    outline: none;
    padding: 0.5rem;
    font-size: 0.9rem;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: 20px;
}

.chat-input input::placeholder {
    color: var(--text-muted-dark);
}

.chat-input i {
    color: var(--accent-primary);
    cursor: pointer;
    transition: opacity 0.3s ease;
    /* 移动端触摸优化 */
    padding: 8px;
    min-width: 32px;
    min-height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.chat-input i:hover {
    opacity: 0.7;
}

/* 用户头像样式 */
.avatar-img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

/* 安全指示器 */
.security-indicator {
    color: #10b981 !important;
    animation: pulse-security 2s infinite;
}

@keyframes pulse-security {
    0%, 100% {
        opacity: 0.7;
    }
    50% {
        opacity: 1;
        filter: drop-shadow(0 0 5px #10b981);
    }
}

/* 加密徽章 */
.encryption-badge {
    position: absolute;
    bottom: -5px;
    right: 5px;
    background: #10b981;
    color: white;
    border-radius: 50%;
    width: 16px;
    height: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 8px;
    box-shadow: 0 2px 5px rgba(16, 185, 129, 0.3);
}

.message {
    position: relative;
}

/* 消息图片样式 */
.message-image {
    width: 100%;
    max-width: 200px;
    height: 120px;
    object-fit: cover;
    border-radius: 12px;
    margin-bottom: 0.5rem;
    transition: all 0.3s ease;
}

.message-image:hover {
    transform: scale(1.02);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.image-message {
    padding: 0.5rem !important;
}

.ai-badge {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.7rem;
    color: #8b5cf6;
    font-weight: 500;
    background: rgba(139, 92, 246, 0.1);
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    margin-top: 0.5rem;
}

.ai-badge i {
    color: #8b5cf6;
}

/* 功能特色 */
.features {
    padding: 80px 0;
    background: var(--bg-primary);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-header p {
    font-size: 1.1rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 
        0 4px 20px var(--shadow-light),
        0 0 0 1px var(--border-color);
    text-align: center;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, var(--glow-color), transparent);
    transition: left 0.5s;
}

.feature-card:hover::before {
    left: 100%;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 
        0 20px 40px var(--shadow-heavy),
        0 0 0 1px var(--border-color);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 2rem;
    position: relative;
    z-index: 1;
}

.feature-icon::after {
    content: '';
    position: absolute;
    top: -5px;
    left: -5px;
    right: -5px;
    bottom: -5px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 50%;
    z-index: -1;
    opacity: 0.3;
    animation: pulse 2s infinite;
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-muted);
    line-height: 1.6;
}

/* 安全特性 */
.security {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
}

.security-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

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

.security-animation {
    position: relative;
    width: 300px;
    height: 300px;
    margin: 0 auto;
}

.lock-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120px;
    height: 120px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
    animation: pulse 2s infinite;
    box-shadow: 0 0 30px var(--glow-color);
}

.encryption-lines {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.line {
    position: absolute;
    background: linear-gradient(90deg, transparent, var(--accent-primary), transparent);
    height: 2px;
    animation: rotate 3s linear infinite;
    box-shadow: 0 0 10px var(--glow-color);
}

.line:nth-child(1) {
    top: 20%;
    width: 80%;
    left: 10%;
    animation-delay: 0s;
}

.line:nth-child(2) {
    top: 50%;
    width: 60%;
    left: 20%;
    animation-delay: 1s;
}

.line:nth-child(3) {
    top: 80%;
    width: 70%;
    left: 15%;
    animation-delay: 2s;
}

@keyframes pulse {
    0%, 100% {
        transform: translate(-50%, -50%) scale(1);
        box-shadow: 0 0 30px var(--glow-color);
    }
    50% {
        transform: translate(-50%, -50%) scale(1.1);
        box-shadow: 0 0 50px var(--glow-color);
    }
}

@keyframes rotate {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

.security-features {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.security-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.security-item i {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    flex-shrink: 0;
    box-shadow: 0 0 20px var(--glow-color);
}

.security-item h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.security-item p {
    color: var(--text-muted);
    line-height: 1.6;
}

/* 下载区域 */
.download {
    padding: 80px 0;
    background: var(--bg-primary);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.download-card {
    background: var(--bg-card);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 
        0 4px 20px var(--shadow-light),
        0 0 0 1px var(--border-color);
    text-align: center;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.download-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, var(--glow-color), transparent);
    transition: left 0.5s;
}

.download-card:hover::before {
    left: 100%;
}

.download-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 
        0 20px 40px var(--shadow-heavy),
        0 0 0 1px var(--border-color);
    border-color: var(--accent-primary);
}

.platform-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 2rem;
    box-shadow: 0 0 30px var(--glow-color);
}

.download-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.download-card p {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.download-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-muted-dark);
}

/* 关于我们 */
.about {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.about-stats {
    display: flex;
    gap: 2rem;
    margin-top: 2rem;
}

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

.about-stat .stat-number {
    display: block;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--accent-primary);
    text-shadow: 0 0 20px var(--glow-color);
}

.about-stat .stat-label {
    font-size: 0.9rem;
    color: var(--text-muted-dark);
}

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

.photo-placeholder {
    width: 300px;
    height: 300px;
    background: var(--bg-card);
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--accent-primary);
    font-size: 1.2rem;
    font-weight: 500;
    box-shadow: 
        0 4px 20px var(--shadow-light),
        0 0 0 1px var(--border-color);
}

.photo-placeholder i {
    font-size: 3rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 页脚 */
.footer {
    background: var(--bg-primary);
    color: var(--text-secondary);
    padding: 60px 0 20px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-logo i {
    margin-right: 0.5rem;
    color: var(--accent-primary);
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-logo .logo-icon {
    margin-right: 0.5rem;
    flex-shrink: 0;
}

.footer-section p {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

/* 联系信息样式 */
.contact-info {
    margin-bottom: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.contact-item i {
    color: var(--accent-primary);
    width: 16px;
}

.contact-item a {
    color: var(--accent-primary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.contact-item a:hover {
    color: var(--accent-secondary);
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(59, 130, 246, 0.1);
    color: var(--accent-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    border: 1px solid rgba(59, 130, 246, 0.2);
}

.social-links a:hover {
    background: var(--accent-primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--glow-color);
}

.footer-section h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-bottom p {
    color: var(--text-muted);
}

.footer-bottom a {
    color: var(--accent-primary);
    text-decoration: none;
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

/* ========================================
   PC端响应式设计 - 大屏幕优化
   ======================================== */

/* 超大屏幕 (2K及以上分辨率) */
@media (min-width: 2560px) {
    .container {
        max-width: 1600px;
    }
    
    .hero-title {
        font-size: 4.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.5rem;
    }
    
    .section-header h2 {
        font-size: 3.2rem;
    }
    
    .section-header p {
        font-size: 1.3rem;
    }
    
    .feature-card,
    .download-card {
        padding: 2.5rem;
    }
    
    .feature-card h3,
    .download-card h3 {
        font-size: 1.6rem;
    }
    
    .feature-card p,
    .download-card p {
        font-size: 1.1rem;
    }
    
    .phone-mockup {
        max-width: 360px;
    }
    
    .phone-screen {
        height: 600px;
    }
}

/* 大屏幕 (1920x1080 全高清) */
@media (min-width: 1920px) and (max-width: 2559px) {
    .container {
        max-width: 1400px;
    }
    
    .hero-title {
        font-size: 4rem;
    }
    
    .hero-subtitle {
        font-size: 1.35rem;
        max-width: 700px;
    }
    
    .section-header h2 {
        font-size: 2.8rem;
    }
    
    .section-header p {
        font-size: 1.2rem;
        max-width: 700px;
    }
    
    .features-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 2.5rem;
    }
    
    .feature-card {
        padding: 2.2rem;
    }
    
    .feature-icon {
        width: 90px;
        height: 90px;
        font-size: 2.2rem;
    }
    
    .phone-mockup {
        max-width: 340px;
    }
    
    .phone-screen {
        height: 560px;
    }
    
    .security-animation {
        width: 350px;
        height: 350px;
    }
    
    .lock-icon {
        width: 140px;
        height: 140px;
        font-size: 3.5rem;
    }
}

/* 标准大屏 (1440px - 1919px) */
@media (min-width: 1440px) and (max-width: 1919px) {
    .container {
        max-width: 1300px;
    }
    
    .hero-title {
        font-size: 3.8rem;
    }
    
    .features-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 2rem;
    }
}

/* 中等屏幕 (1200px - 1439px) */
@media (min-width: 1200px) and (max-width: 1439px) {
    .container {
        max-width: 1140px;
    }
    
    .hero-title {
        font-size: 3.2rem;
    }
    
    .features-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* 小型桌面/大平板 (1024px - 1199px) */
@media (min-width: 1024px) and (max-width: 1199px) {
    .container {
        max-width: 960px;
    }
    
    .hero-title {
        font-size: 2.8rem;
    }
    
    .hero-container {
        gap: 2rem;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .phone-mockup {
        max-width: 260px;
    }
    
    .phone-screen {
        height: 420px;
    }
}

/* ========================================
   移动端响应式设计 - 基于主流手机尺寸优化
   ======================================== */

/* 平板设备 (769px - 1023px) */
@media (min-width: 769px) and (max-width: 1023px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-container {
        gap: 2rem;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .security-content {
        gap: 2rem;
    }
    
    .phone-mockup {
        max-width: 250px;
    }
    
    .phone-screen {
        height: 400px;
    }
    
    .nav-menu {
        gap: 1rem;
    }
    
    .nav-menu a {
        font-size: 0.9rem;
    }
}

/* 大屏手机 (iPhone 14 Pro Max, Samsung Galaxy S23 Ultra 等 430px) */
@media (max-width: 430px) {
    .hero-title {
        font-size: 2.2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .section-header h2 {
        font-size: 1.8rem;
    }
    
    .phone-mockup {
        max-width: 280px;
    }
    
    .phone-screen {
        height: 450px;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: 1rem;
    }
    
    .btn-large {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
}

/* 中等屏幕手机 (iPhone 12, iPhone 13, Samsung Galaxy S21 等) */
@media (max-width: 390px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 0.95rem;
    }
    
    .section-header h2 {
        font-size: 1.6rem;
    }
    
    .phone-mockup {
        max-width: 260px;
    }
    
    .phone-screen {
        height: 420px;
    }
    
    .feature-card,
    .download-card {
        padding: 1.5rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }
    
    .about-stats {
        flex-direction: column;
        gap: 1rem;
    }
}

/* 小屏手机 (iPhone SE, iPhone 12 mini 等) */
@media (max-width: 375px) {
    .hero-title {
        font-size: 1.8rem;
    }
    
    .hero-subtitle {
        font-size: 0.9rem;
    }
    
    .section-header h2 {
        font-size: 1.5rem;
    }
    
    .phone-mockup {
        max-width: 240px;
    }
    
    .phone-screen {
        height: 380px;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .feature-card,
    .download-card {
        padding: 1.25rem;
    }
    
    .nav-container {
        padding: 0 15px;
    }
}

/* 超小屏手机 (iPhone SE 第一代等) */
@media (max-width: 320px) {
    .hero-title {
        font-size: 1.6rem;
    }
    
    .hero-subtitle {
        font-size: 0.85rem;
    }
    
    .section-header h2 {
        font-size: 1.3rem;
    }
    
    .phone-mockup {
        max-width: 220px;
    }
    
    .phone-screen {
        height: 350px;
    }
    
    .container {
        padding: 0 12px;
    }
    
    .nav-container {
        padding: 0 12px;
    }
    
    .feature-card,
    .download-card {
        padding: 1rem;
    }
    
    .btn-large {
        padding: 0.75rem 1.25rem;
        font-size: 0.9rem;
    }
}

/* 平板设备 */
@media (min-width: 768px) and (max-width: 1024px) {
    .hero-title {
        font-size: 3rem;
    }
    
    .hero-container {
        gap: 3rem;
    }
    
    .security-content {
        gap: 3rem;
    }
    
    .phone-mockup {
        max-width: 280px;
    }
    
    .phone-screen {
        height: 450px;
    }
}

/* 通用移动端优化 */
@media (max-width: 768px) {
    /* 移动端导航菜单 - 侧边滑出 */
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: min(280px, 80vw);
        height: 100vh;
        height: 100dvh; /* 动态视口高度，适配iOS Safari */
        background: var(--bg-primary);
        flex-direction: column;
        padding: 80px 20px 30px;
        gap: 0;
        transition: right 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        box-shadow: -5px 0 20px var(--shadow-heavy);
        z-index: 999;
        display: flex;
        overflow-y: auto;
    }
    
    .nav-menu.active {
        right: 0;
    }
    
    .nav-menu li {
        width: 100%;
        border-bottom: 1px solid var(--border-color);
    }
    
    .nav-menu a {
        display: block;
        padding: 15px 10px;
        font-size: 1.1rem;
        width: 100%;
    }
    
    .nav-menu a::after {
        display: none;
    }
    
    /* 移动端导航按钮区域 */
    .nav-buttons {
        display: flex;
        gap: 0.5rem;
    }
    
    .contact-email {
        display: none;
    }
    
    /* 移动端主题和语言切换按钮 */
    .theme-toggle,
    .lang-toggle {
        display: flex;
        width: 36px;
        height: 36px;
        min-width: 36px;
        min-height: 36px;
        padding: 0;
        font-size: 0.85rem;
    }
    
    .lang-toggle {
        width: auto;
        padding: 0 10px;
    }
    
    .lang-text {
        font-size: 0.75rem;
    }
    
    .hamburger {
        display: flex;
        z-index: 1001;
    }
    
    /* 移动端菜单内的额外按钮区域 */
    .mobile-menu-extras {
        display: flex;
        flex-direction: column;
        gap: 15px;
        margin-top: 20px;
        padding-top: 20px;
        border-top: 1px solid var(--border-color);
    }
    
    .mobile-menu-extras .contact-email {
        display: flex;
        justify-content: center;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-stats {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .security-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .security-features {
        text-align: left;
    }
    
    .download-grid {
        grid-template-columns: 1fr;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .about-stats {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    /* 移动端触摸优化 */
    .nav-menu a,
    .btn-primary,
    .btn-secondary,
    .btn-outline,
    .theme-toggle,
    .lang-toggle,
    .hamburger {
        min-height: 44px;
    }
    
    /* 移动端字体优化 */
    body {
        font-size: 16px; /* 防止iOS缩放 */
    }
    
    /* 移动端滚动优化 */
    .chat-messages {
        -webkit-overflow-scrolling: touch;
    }
    
    /* 移动端遮罩层 */
    .nav-overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        z-index: 998;
        backdrop-filter: blur(2px);
        -webkit-backdrop-filter: blur(2px);
    }
    
    .nav-overlay.active {
        display: block;
    }
    
    /* 移动端菜单内额外按钮区域 */
    .mobile-menu-extras {
        display: flex !important;
        flex-direction: column;
        gap: 15px;
        margin-top: 20px;
        padding-top: 20px;
        border-top: 1px solid var(--border-color);
        border-bottom: none !important;
    }
    
    .mobile-menu-buttons {
        display: flex;
        flex-direction: column;
        gap: 12px;
    }
    
    .mobile-theme-toggle,
    .mobile-lang-toggle {
        display: flex !important;
        align-items: center;
        justify-content: flex-start;
        gap: 12px;
        width: 100%;
        padding: 12px 15px;
        border-radius: 10px;
        background: var(--bg-secondary);
        border: 1px solid var(--border-color);
        color: var(--text-primary);
        font-size: 1rem;
        cursor: pointer;
        transition: all 0.3s ease;
    }
    
    .mobile-theme-toggle:hover,
    .mobile-lang-toggle:hover {
        background: var(--accent-primary);
        color: white;
        border-color: var(--accent-primary);
    }
    
    .mobile-theme-toggle i,
    .mobile-lang-toggle i {
        font-size: 1.2rem;
        width: 24px;
        text-align: center;
    }
    
    .mobile-lang-toggle .lang-text {
        background: var(--accent-primary);
        color: white;
        padding: 2px 8px;
        border-radius: 4px;
        font-size: 0.85rem;
        font-weight: 600;
    }
    
    .mobile-contact {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 10px;
        padding: 15px;
        background: var(--bg-secondary);
        border-radius: 10px;
        color: var(--text-secondary);
    }
    
    .mobile-contact i {
        color: var(--accent-primary);
    }
    
    .mobile-contact a {
        color: var(--accent-primary);
        text-decoration: none;
        font-weight: 500;
    }
    
    .mobile-contact a:hover {
        text-decoration: underline;
    }
}

/* PC端隐藏移动端专用元素 */
@media (min-width: 769px) {
    .mobile-menu-extras {
        display: none !important;
    }
    
    .nav-overlay {
        display: none !important;
    }
}

/* 横屏模式优化 */
@media (max-height: 500px) and (orientation: landscape) {
    .hero {
        min-height: auto;
        padding: 80px 0 40px;
    }
    
    .hero-container {
        gap: 2rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .phone-mockup {
        max-width: 200px;
    }
    
    .phone-screen {
        height: 300px;
    }
}

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

.feature-card,
.download-card,
.security-item {
    animation: fadeInUp 0.6s ease forwards;
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}

/* 联系弹窗样式 */
.contact-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 10000;
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter: blur(5px);
}

.contact-modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-card);
    border-radius: 16px;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 20px 40px var(--shadow-heavy);
    border: 1px solid var(--border-color);
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-50px) scale(0.9);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    color: var(--text-primary);
    font-size: 1.3rem;
    font-weight: 600;
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: all 0.3s ease;
    min-width: 44px;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-close:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.modal-body {
    padding: 1.5rem;
}

.modal-body p {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.contact-options {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.contact-option {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-tertiary);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.contact-option:hover {
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.contact-option i {
    font-size: 1.5rem;
    color: var(--accent-primary);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(59, 130, 246, 0.1);
    border-radius: 50%;
}

.contact-details h4 {
    color: var(--text-primary);
    margin: 0 0 0.25rem 0;
    font-size: 1rem;
    font-weight: 600;
}

.contact-details a {
    color: var(--accent-primary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.contact-details a:hover {
    color: var(--accent-secondary);
}

.modal-footer {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.modal-footer .btn-primary,
.modal-footer .btn-outline {
    flex: 1;
    justify-content: center;
}

/* 移动端滚动条隐藏 */
@media (max-width: 768px) {
    ::-webkit-scrollbar {
        width: 0;
        background: transparent;
    }
    
    .modal-content {
        width: 95%;
        margin: 1rem;
    }
    
    .modal-footer {
        flex-direction: column;
    }
    
    .contact-option {
        flex-direction: column;
        text-align: center;
        gap: 0.5rem;
    }
} 

.solution-card p { 
  font-size: 1rem; 
  color: var(--card-text-muted); 
}

/* 解决方案版块样式 */
.solutions { 
  padding: 60px 0; 
  background: var(--section-bg);
} 
.solutions-grid { 
  display: flex; 
  flex-wrap: wrap; 
  gap: 32px; 
  justify-content: center; 
} 
.solution-card {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 32px 24px;
  flex: 1 1 260px;
  min-width: 260px;
  max-width: 340px;
  text-align: center;
  color: var(--card-text);
  box-shadow: 0 4px 24px var(--shadow-light);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  border: 1px solid var(--border-color);
}
.solution-card:hover { 
  transform: translateY(-8px) scale(1.03); 
  box-shadow: 0 8px 32px var(--shadow-heavy);
} 
.solution-card i { 
  font-size: 2.5rem; 
  margin-bottom: 16px; 
  color: var(--accent-primary); 
} 
.solution-card h3 { 
  margin: 12px 0 8px; 
  font-size: 1.25rem; 
  color: var(--card-text);
} 
.solution-card p { 
  font-size: 1rem; 
  color: var(--card-text-muted); 
}

.cases { 
  padding: 60px 0; 
  background: var(--section-bg); 
} 
.cases-grid { 
  display: grid; 
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); 
  gap: 24px; 
  margin: 40px 0; 
  max-width: 1000px; 
  margin-left: auto; 
  margin-right: auto; 
}
.case-card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 32px 24px;
  text-align: center;
  box-shadow: 0 4px 16px var(--shadow-light);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  border: 1px solid var(--border-color);
  color: var(--card-text);
}
.case-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px var(--shadow-heavy);
}
.case-logo {
  margin-bottom: 16px;
}
.case-logo i {
  font-size: 2.5rem;
  color: #4f8cff;
  background: linear-gradient(135deg, #4f8cff, #3578e5);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: all 0.3s ease;
  filter: drop-shadow(0 2px 4px rgba(79, 140, 255, 0.2));
}

.case-card:hover .case-logo i {
  transform: scale(1.1) rotate(5deg);
  filter: drop-shadow(0 4px 8px rgba(79, 140, 255, 0.4));
  background: linear-gradient(135deg, #3578e5, #4f8cff, #06b6d4);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* 为不同企业设置不同的图标颜色 */
.case-card:nth-child(1) .case-logo i { /* Apple */
  background: linear-gradient(135deg, #000000, #333333);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(2) .case-logo i { /* Microsoft */
  background: linear-gradient(135deg, #00a4ef, #7fba00);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(3) .case-logo i { /* Google */
  background: linear-gradient(135deg, #4285f4, #ea4335, #fbbc05, #34a853);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(4) .case-logo i { /* Amazon */
  background: linear-gradient(135deg, #ff9900, #232f3e);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(5) .case-logo i { /* Meta */
  background: linear-gradient(135deg, #1877f2, #42a5f5);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(6) .case-logo i { /* 腾讯 */
  background: linear-gradient(135deg, #07c160, #1aad19);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(7) .case-logo i { /* 阿里巴巴 */
  background: linear-gradient(135deg, #ff6a00, #ee1c25);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(8) .case-logo i { /* 华为 */
  background: linear-gradient(135deg, #c7000b, #ff0000);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(9) .case-logo i { /* 百度 */
  background: linear-gradient(135deg, #2932e1, #4e6ef2);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(10) .case-logo i { /* 网易 */
  background: linear-gradient(135deg, #e60012, #ff6b6b);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(11) .case-logo i { /* 比亚迪 */
  background: linear-gradient(135deg, #e60012, #ff6b6b);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(12) .case-logo i { /* 万科 */
  background: linear-gradient(135deg, #1e3a8a, #3b82f6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(13) .case-logo i { /* Netflix */
  background: linear-gradient(135deg, #e50914, #b81d24);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.case-card:nth-child(14) .case-logo i { /* Spotify */
  background: linear-gradient(135deg, #1db954, #1ed760);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .cases-grid {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 16px;
  }
  .case-card {
    padding: 24px 16px;
  }
  .case-logo i {
    font-size: 2rem;
  }
  .case-card h4 {
    font-size: 0.9rem;
  }
} 

/* 案例卡片增强样式 */
.case-content {
    padding: 1rem 0 0 0;
}

.case-description {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.5;
    margin: 0.75rem 0 1rem 0;
    opacity: 0.9;
}

.case-stats {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1rem;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.75rem;
    color: var(--accent-primary);
    font-weight: 500;
    padding: 0.25rem 0.5rem;
    background: rgba(59, 130, 246, 0.1);
    border-radius: 12px;
    border: 1px solid rgba(59, 130, 246, 0.2);
    transition: all 0.3s ease;
}

.stat-item i {
    font-size: 0.8rem;
}

/* 增强案例卡片交互 */
.case-card:hover .case-description {
    opacity: 1;
}

.case-card:hover .stat-item {
    background: rgba(59, 130, 246, 0.2);
    transform: scale(1.05);
}

.cases-cta {
  text-align: center;
  margin-top: 40px;
} 

/* 移动端优化 */
@media (max-width: 768px) {
    .solutions-grid {
        flex-direction: column;
        align-items: center;
    }
    
    .solution-card {
        flex: none;
        width: 100%;
        max-width: 320px;
        margin-bottom: 20px;
    }
    
    .cases-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: 16px;
    }
    
    .case-card {
        padding: 24px 16px;
    }
    
    .case-logo i {
        font-size: 2rem;
    }
    
    .case-card h4 {
        font-size: 0.9rem;
    }
    
    /* 触摸优化 */
    .solution-card,
    .case-card,
    .feature-card,
    .download-card {
        -webkit-tap-highlight-color: transparent;
        touch-action: manipulation;
    }
    
    /* 防止移动端缩放 */
    input, textarea, select {
        font-size: 16px !important;
    }
}

/* 超小屏幕优化 */
@media (max-width: 480px) {
    .solutions-grid {
        gap: 16px;
    }
    
    .solution-card {
        padding: 20px 16px;
        min-width: 280px;
    }
    
    .cases-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }
    
    .case-card {
        padding: 20px 12px;
    }
    
    .case-logo i {
        font-size: 1.8rem;
    }
    
    .case-card h4 {
        font-size: 0.8rem;
    }
}

/* 横屏模式优化 */
@media (orientation: landscape) and (max-height: 500px) {
    .solutions {
        padding: 40px 0;
    }
    
    .solution-card {
        padding: 20px 16px;
    }
    
    .cases {
        padding: 40px 0;
    }
    
    .case-card {
        padding: 20px 16px;
    }
}

/* 离线指示器 */
.offline-indicator {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: #ef4444;
    color: white;
    text-align: center;
    padding: 0.5rem;
    font-size: 0.9rem;
    z-index: 10001;
    transform: translateY(-100%);
    transition: transform 0.3s ease;
}

.offline-indicator.show {
    transform: translateY(0);
}

.offline-indicator i {
    margin-right: 0.5rem;
}

/* 加载状态指示器 */
.loading-spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(59, 130, 246, 0.3);
    border-radius: 50%;
    border-top-color: var(--accent-primary);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
    :root {
        --text-primary: #000000;
        --text-secondary: #000000;
        --bg-primary: #ffffff;
        --bg-secondary: #f5f5f5;
        --accent-primary: #0000ff;
        --border-color: #000000;
    }
}

/* 减少动画偏好支持 */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    
    .phone-mockup::before,
    .feature-icon::after,
    .security-indicator,
    .encryption-lines .line {
        animation: none !important;
    }
}

/* 打印样式 */
@media print {
    .navbar, .hamburger, .theme-toggle, .lang-toggle {
        display: none !important;
    }
    
    .hero {
        padding-top: 0;
        min-height: auto;
    }
    
    .phone-mockup, .security-animation {
        display: none;
    }
    
    body {
        background: white !important;
        color: black !important;
    }
    
    .feature-card, .case-card, .download-card {
        break-inside: avoid;
        border: 1px solid #ccc !important;
        margin-bottom: 1rem;
    }
}