/* ================================
   全局样式和变量
   ================================ */
:root {
    /* 主题色 */
    --primary-color: #0066ff;
    --primary-dark: #0052cc;
    --primary-light: #3385ff;
    --secondary-color: #00d4ff;
    --accent-color: #ff6b00;
    
    /* 渐变色 */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-blue: linear-gradient(135deg, #0066ff 0%, #00d4ff 100%);
    --gradient-purple: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-tech: linear-gradient(135deg, #1e3c72 0%, #2a5298 50%, #7e22ce 100%);
    
    /* 中性色 */
    --dark: #0a0e27;
    --dark-light: #1a1f3a;
    --gray-dark: #2d3748;
    --gray: #4a5568;
    --gray-light: #cbd5e0;
    --gray-lighter: #e2e8f0;
    --white: #ffffff;
    
    /* 文字颜色 */
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-light: #718096;
    
    /* 间距 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* 字体 */
    --font-primary: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    --font-mono: 'Courier New', Courier, monospace;
    
    /* 阴影 */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1);
    --shadow-glow: 0 0 20px rgba(0, 102, 255, 0.3);
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* 边框圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 20px;
}

/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    color: var(--text-primary);
    line-height: 1.6;
    background-color: var(--white);
    overflow-x: hidden;
    }

html {
    overflow-x: clip;
}

/* 隐藏滚动条但保持功能 */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--gray-lighter);
}

::-webkit-scrollbar-thumb {
    background: var(--gray);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-dark);
}

/* 文本选择样式 */
::selection {
    background-color: var(--primary-color);
    color: var(--white);
}

/* 通用容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 14px 32px;
    font-size: 16px;
    font-weight: 600;
    text-align: center;
    text-decoration: none;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: var(--gradient-blue);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

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

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

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

.btn-block {
    width: 100%;
}

/* ================================
   导航栏
   ================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    background: var(--gradient-blue);
    color: var(--white);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
}

.logo-text {
    color: var(--dark);
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    position: relative;
    transition: color var(--transition-base);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-blue);
    transition: width var(--transition-base);
}

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

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

/* 移动端菜单按钮 */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--dark);
    border-radius: 3px;
    transition: all var(--transition-base);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}

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

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* ================================
   Hero 区域
   ================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-tech);
    color: var(--white);
    overflow: hidden;
    padding-top: 80px;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

#particleCanvas {
    width: 100%;
    height: 100%;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 900px;
    animation: fadeInUp 1s ease;
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.title-line {
    display: block;
    background: linear-gradient(135deg, #fff 0%, #00d4ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 300;
    margin-bottom: var(--spacing-sm);
    opacity: 0.9;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: var(--spacing-xl);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
    margin-top: var(--spacing-xl);
}

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

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, #fff 0%, #00d4ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.8;
    margin-top: 0.5rem;
}

/* 滚动指示器 */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.mouse {
    width: 26px;
    height: 40px;
    border: 2px solid rgba(255, 255, 255, 0.5);
    border-radius: 20px;
    display: flex;
    justify-content: center;
    padding-top: 8px;
}

.wheel {
    width: 4px;
    height: 8px;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 2px;
    animation: scroll 2s infinite;
}

@keyframes scroll {
    0%, 100% { opacity: 0; transform: translateY(0); }
    50% { opacity: 1; transform: translateY(10px); }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ================================
   区块标题
   ================================ */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: var(--spacing-sm);
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--gradient-blue);
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-top: 1.5rem;
}

/* ================================
   服务项目
   ================================ */
.services {
    padding: var(--spacing-xl) 0;
    background: var(--white);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.service-card {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    border: 1px solid var(--gray-lighter);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.service-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-blue);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: var(--white);
}

.service-icon svg {
    width: 30px;
    height: 30px;
}

.service-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--dark);
}

.service-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.service-features {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
}

.service-features li {
    color: var(--text-light);
    padding-left: 1.5rem;
    position: relative;
}

.service-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

/* ================================
   解决方案
   ================================ */
.solutions {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

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

.solution-card {
    background: var(--white);
    padding: 2.5rem;
    border-radius: var(--radius-xl);
    position: relative;
    overflow: hidden;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-md);
}

.solution-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-blue);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-base);
}

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

.solution-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.solution-number {
    font-size: 3rem;
    font-weight: 700;
    background: var(--gradient-blue);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
}

.solution-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--dark);
}

.solution-card p {
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ================================
   技术栈
   ================================ */
.tech-stack {
    padding: var(--spacing-xl) 0;
    background: var(--white);
    overflow: hidden;
    position: relative;
    }

.tech-categories {
    display: grid;
    gap: 2rem;
}

.tech-category {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    border-left: 4px solid var(--primary-color);
}

.tech-category h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--dark);
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.tech-tag {
    padding: 0.5rem 1.5rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-base);
    cursor: default;
}

.tech-tag:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

/* ================================
   成功案例
   ================================ */
.cases {
    padding: var(--spacing-xl) 0;
    background: var(--gray-lighter);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

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

.case-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.case-image {
    width: 100%;
    height: 250px;
    overflow: hidden;
    position: relative;
}

.case-placeholder {
    width: 100%;
    height: 100%;
    background: var(--gradient-tech);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.5rem;
    font-weight: 600;
}

.case-content {
    padding: 2rem;
}

.case-content h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--dark);
}

.case-content p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.case-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.case-tags span {
    padding: 0.4rem 1rem;
    background: var(--gray-lighter);
    border-radius: 50px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ================================
   关于我们
   ================================ */
.about {
    padding: var(--spacing-xl) 0;
    background: var(--white);
}

.about-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.6fr;
    gap: 4rem;
    align-items: start;
    }

.about-video {
    border-radius: var(--radius-xl, 16px);
    overflow: hidden;
    box-shadow: var(--shadow-lg, 0 20px 60px rgba(15, 23, 42, 0.15));
    background: #000;
    -webkit-touch-callout: none;
}

.about-video video {
    display: block;
    width: 100%;
    aspect-ratio: 4 / 3;
    object-fit: cover;
    background: #000;
    -webkit-touch-callout: none;
    user-select: none;
}

.about-video-loading {
    position: absolute;
    left: 0;
    right: 0;
    top: 45%;
    text-align: center;
    color: rgba(255, 255, 255, 0.9);
    font-size: 14px;
    letter-spacing: 1px;
    pointer-events: none;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.6);
}

/* ---------- 自定义视频控件（无原生控件 = 无原生下载按钮） ---------- */
.av-player {
    position: relative;
}
.av-player video {
    pointer-events: none; /* 手机长按/右键无法命中视频本体，杜绝长按下载菜单 */
    -webkit-touch-callout: none;
}
.av-center-play {
    position: absolute;
    left: 50%;
    top: 44%;
    transform: translate(-50%, -50%);
    width: 64px;
    height: 64px;
    border: none;
    border-radius: 50%;
    background: rgba(0, 102, 255, 0.85);
    color: #fff;
    font-size: 22px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
    transition: opacity 0.25s, transform 0.25s;
    padding-left: 6px;
    z-index: 3;
}
.av-center-play.hide {
    opacity: 0;
    pointer-events: none;
    transform: translate(-50%, -50%) scale(0.8);
}
.av-bar {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.72));
    opacity: 1;
    transition: opacity 0.25s;
    z-index: 3;
}
.av-player.playing .av-bar {
    opacity: 0;
}
.av-player.playing:hover .av-bar,
.av-player.playing.touching .av-bar {
    opacity: 1;
}
.av-toggle {
    border: none;
    background: transparent;
    color: #fff;
    font-size: 13px;
    cursor: pointer;
    padding: 4px 2px;
    flex: 0 0 auto;
}
.av-progress {
    flex: 1;
    height: 22px;
    display: flex;
    align-items: center;
    cursor: pointer;
    touch-action: none;
}
.av-progress::before {
    content: '';
    position: absolute;
    left: 12px;
    right: 12px;
    height: 4px;
    border-radius: 2px;
    background: rgba(255, 255, 255, 0.28);
}
.av-played {
    position: relative;
    width: 0%;
    height: 4px;
    border-radius: 2px;
    background: var(--primary, #0066ff);
    z-index: 1;
}
.av-dot {
    position: absolute;
    right: -7px;
    top: 50%;
    transform: translateY(-50%);
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.4);
}
.av-time {
    color: rgba(255, 255, 255, 0.92);
    font-size: 12px;
    flex: 0 0 auto;
    font-variant-numeric: tabular-nums;
}

/* 隐藏原生全屏按钮 */
.about-video video::-webkit-media-controls-fullscreen-button {
    display: none !important;
}

.about-text {
    margin-bottom: 2rem;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.8;
}

.about-features {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

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

.feature-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-blue);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-weight: 700;
    flex-shrink: 0;
}

.feature-text h4 {
    color: var(--dark);
    margin-bottom: 0.5rem;
}

.feature-text p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.about-image {
    position: relative;
    height: 500px;
}

.about-image-placeholder {
    width: 100%;
    height: 100%;
    background: var(--gradient-tech);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.tech-circle {
    position: absolute;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 50%;
}

.tech-circle:nth-child(1) {
    width: 200px;
    height: 200px;
    animation: rotate 20s linear infinite;
}

.tech-circle:nth-child(2) {
    width: 300px;
    height: 300px;
    animation: rotate 30s linear infinite reverse;
}

.tech-circle:nth-child(3) {
    width: 400px;
    height: 400px;
    animation: rotate 40s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* ================================
   联系我们
   ================================ */
.contact {
    padding: var(--spacing-xl) 0;
    background: var(--gray-lighter);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    gap: 1.5rem;
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-blue);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    flex-shrink: 0;
}

.contact-icon svg {
    width: 24px;
    height: 24px;
}

.contact-details h4 {
    color: var(--dark);
    margin-bottom: 0.5rem;
}

.contact-details p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* 联系表单 */
.contact-form {
    background: var(--white);
    padding: 2.5rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--gray-lighter);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    transition: all var(--transition-base);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

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

/* ================================
   页脚
   ================================ */
.footer {
    background: var(--dark);
    color: var(--white);
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: 1.6fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: var(--spacing-md);
    }

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1.5rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
    margin-bottom: 1rem;
}

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

.footer-section ul li {
    margin-bottom: 0.8rem;
}

.footer-section ul li a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color var(--transition-base);
}

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

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

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    transition: all var(--transition-base);
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
}

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

/* ================================
   返回顶部按钮
   ================================ */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-blue);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-lg);
    z-index: 999;
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

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

/* ================================
   响应式设计
   ================================ */

/* 平板设备 */
@media (max-width: 1024px) {
    :root {
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }
    
    .hero-title {
        font-size: 3rem;
    }
    
    .hero-stats {
        gap: 2rem;
    }
    
    .about-wrapper,
    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .services-grid,
    .cases-grid {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    }
}

/* 手机设备 */
@media (max-width: 768px) {
    :root {
        --spacing-md: 1.5rem;
        --spacing-lg: 2rem;
        --spacing-xl: 3rem;
    }
    
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow-lg);
        transform: translateX(-100%);
        transition: transform var(--transition-base);
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .hero {
        min-height: 90vh;
        padding-top: 70px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .services-grid,
    .solutions-grid,
    .cases-grid {
        grid-template-columns: 1fr;
    }
    
    .service-features {
        grid-template-columns: 1fr;
    }
    
    .tech-tags {
        gap: 0.5rem;
    }
    
    .about-image {
        height: 300px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    /* 手机端左右入场位移改为纯淡入，避免横向偏移观感 */
    [data-aos="fade-right"],
    [data-aos="fade-left"] {
        transform: none;
    }
}

/* 小屏手机 */
@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .btn {
        padding: 12px 24px;
        font-size: 14px;
    }
    
    .service-card,
    .solution-card,
    .case-card {
        padding: 1.5rem;
    }
}

/* 动画类 */
[data-aos] {
    opacity: 0;
    transition: all 0.8s ease;
}

[data-aos].aos-animate {
    opacity: 1;
}

[data-aos="fade-up"] {
    transform: translateY(30px);
}

[data-aos="fade-up"].aos-animate {
    transform: translateY(0);
}

[data-aos="fade-right"] {
    transform: translateX(-30px);
}

[data-aos="fade-right"].aos-animate {
    transform: translateX(0);
}

[data-aos="fade-left"] {
    transform: translateX(30px);
}

[data-aos="fade-left"].aos-animate {
    transform: translateX(0);
}

[data-aos="zoom-in"] {
    transform: scale(0.9);
}

[data-aos="zoom-in"].aos-animate {
    transform: scale(1);
}

/* 加载动画 */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in {
    animation: fadeIn 1s ease;
}

/* ---------- 导航 Logo 图片 ---------- */
.logo-img {
    height: 42px;
    width: auto;
    max-width: 180px;
    object-fit: contain;
    display: block;
    border-radius: 6px;
}

/* ---------- 成功案例：自动滚动跑马灯 ---------- */
.cases-marquee {
    overflow: hidden;
    position: relative;
    width: 100vw;
    margin-left: calc(50% - 50vw);
    margin-right: 0;
    padding: 0;
    -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 6%, #000 94%, transparent 100%);
    mask-image: linear-gradient(90deg, transparent 0, #000 6%, #000 94%, transparent 100%);
    touch-action: pan-y;
}
.cases-track {
    display: flex;
    gap: 30px;
    width: max-content;
    will-change: transform;
}

@keyframes casesScroll {
    from { transform: translateX(0); }
    to { transform: translateX(-50%); }
}
.cases-track .case-card {
    flex: 0 0 360px;
    max-width: 360px;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
    background: var(--bg-card, #fff);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.cases-track .case-card:hover {
    transform: translateY(-6px);
}

/* ---------- 案例详情页 ---------- */
.case-detail {
    padding: 40px 0 100px;
    background: var(--bg-light, #f8fafc);
    min-height: 60vh;
}
.cd-breadcrumb {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 14px;
    color: var(--text-secondary, #64748b);
    margin-bottom: 26px;
}
.cd-breadcrumb a {
    color: var(--text-secondary, #64748b);
    text-decoration: none;
    transition: color 0.2s;
}
.cd-breadcrumb a:hover {
    color: var(--primary, #0066ff);
}
.cd-breadcrumb em {
    color: var(--text-primary, #1e293b);
    font-style: normal;
}
.cd-cover {
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(15, 23, 42, 0.12);
    max-height: 520px;
    margin-bottom: 40px;
    background: linear-gradient(135deg, var(--primary, #0066ff), var(--primary-dark, #0044cc));
}
.cd-cover img {
    width: 100%;
    max-height: 520px;
    object-fit: cover;
    display: block;
}
.cd-cover .case-placeholder {
    height: 320px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.9);
    letter-spacing: 4px;
}
.cd-header {
    margin-bottom: 30px;
}
.cd-title {
    font-size: 34px;
    font-weight: 700;
    color: var(--text-primary, #1e293b);
    margin-bottom: 14px;
    line-height: 1.3;
}
.cd-desc {
    font-size: 16px;
    color: var(--text-secondary, #64748b);
    line-height: 1.8;
    margin-bottom: 18px;
}
.cd-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}
.cd-tags span {
    padding: 5px 14px;
    border-radius: 999px;
    background: rgba(0, 102, 255, 0.08);
    color: var(--primary, #0066ff);
    font-size: 13px;
    font-weight: 500;
}
.cd-body {
    background: #fff;
    border-radius: 14px;
    padding: 34px 38px;
    box-shadow: 0 6px 24px rgba(15, 23, 42, 0.06);
}
.cd-body p {
    font-size: 16px;
    line-height: 2;
    color: var(--text-primary, #334155);
    margin-bottom: 16px;
}
.cd-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 36px;
}
.cd-gallery-item {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 6px 20px rgba(15, 23, 42, 0.08);
    background: #fff;
}
.cd-gallery-item img {
    width: 100%;
    height: 220px;
    object-fit: cover;
    display: block;
    transition: transform 0.4s ease;
}
.cd-gallery-item:hover img {
    transform: scale(1.04);
}
.cd-actions {
    display: flex;
    gap: 16px;
    margin-top: 44px;
    justify-content: center;
}

@media (max-width: 768px) {
    .logo-img {
        height: 32px;
        max-width: 130px;
    }
    .cases-track .case-card {
        flex: 0 0 280px;
        max-width: 280px;
    }
    .cd-title {
        font-size: 24px;
    }
    .cd-body {
        padding: 22px 18px;
    }
}

/* ---------- 知识分享列表页 ---------- */
.knowledge-list {
    padding: 60px 0 100px;
    background: var(--bg-light, #f8fafc);
    min-height: 60vh;
}
.kb-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 28px;
    margin-top: 40px;
}
.kb-card {
    display: flex;
    flex-direction: column;
    background: #fff;
    border-radius: 14px;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 6px 24px rgba(15, 23, 42, 0.06);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.kb-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 18px 44px rgba(15, 23, 42, 0.12);
}
.kb-cover {
    height: 200px;
    overflow: hidden;
    background: linear-gradient(135deg, var(--primary, #0066ff), var(--primary-dark, #0044cc));
}
.kb-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform 0.4s ease;
}
.kb-card:hover .kb-cover img {
    transform: scale(1.05);
}
.kb-cover-ph {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: rgba(255, 255, 255, 0.92);
    font-size: 26px;
    font-weight: 700;
    letter-spacing: 4px;
}
.kb-info {
    padding: 22px 24px 26px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.kb-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    font-size: 13px;
}
.kb-meta-dark {
    margin-bottom: 12px;
}
.kb-date {
    color: var(--text-secondary, #64748b);
}
.kb-tag {
    padding: 3px 12px;
    border-radius: 999px;
    background: rgba(0, 102, 255, 0.08);
    color: var(--primary, #0066ff);
    font-weight: 500;
}
.kb-title {
    font-size: 19px;
    font-weight: 700;
    color: var(--text-primary, #1e293b);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.kb-summary {
    font-size: 14px;
    color: var(--text-secondary, #64748b);
    line-height: 1.8;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin: 0;
}
.kb-more {
    color: var(--primary, #0066ff);
    font-size: 14px;
    font-weight: 600;
    margin-top: 4px;
}
.kb-empty {
    grid-column: 1 / -1;
    text-align: center;
    color: var(--text-secondary, #64748b);
    padding: 60px 0;
}

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

/* ---------- 知识文章富文本正文 ---------- */
.kb-rich-body {
    font-size: 16px;
    line-height: 2;
    color: #334155;
    word-break: break-word;
}
.kb-rich-body p {
    margin: 0 0 16px;
}
.kb-rich-body h2 {
    font-size: 24px;
    font-weight: 700;
    color: #1e293b;
    margin: 26px 0 12px;
    line-height: 1.4;
}
.kb-rich-body h3 {
    font-size: 20px;
    font-weight: 700;
    color: #1e293b;
    margin: 22px 0 10px;
    line-height: 1.4;
}
.kb-rich-body blockquote {
    margin: 16px 0;
    padding: 12px 18px;
    border-left: 4px solid var(--primary, #0066ff);
    background: rgba(0, 102, 255, 0.05);
    color: #475569;
    border-radius: 0 8px 8px 0;
}
.kb-rich-body ul, .kb-rich-body ol {
    margin: 0 0 16px;
    padding-left: 26px;
}
.kb-rich-body li {
    margin-bottom: 6px;
}
.kb-rich-body img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 4px 16px rgba(15, 23, 42, 0.08);
}
.kb-rich-body figure {
    margin: 22px 0;
    text-align: center;
}
.kb-rich-body figcaption {
    margin-top: 8px;
    font-size: 13px;
    color: #94a3b8;
}
.kb-rich-body a {
    color: var(--primary, #0066ff);
}

/* ---------- 手机端专项修正 ---------- */
@media (max-width: 768px) {
    /* 导航栏实际高度约86px，Hero 顶部留足空间避免标题被压住 */
    .hero {
        padding-top: 110px;
        padding-bottom: 48px;
    }
    /* 手机端隐藏下滑鼠标指示，避免压住统计数字 */
    .scroll-indicator {
        display: none;
    }
    /* 页脚栏目：双列铺满 + 居中 */
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem 1rem;
    }
    .footer-section {
        text-align: center;
    }
    .footer-section ul {
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 0.35rem;
    }
    .footer-section .social-links {
        justify-content: center;
    }
    .footer-bottom {
        text-align: center;
    }
    .footer-bottom p {
        line-height: 1.8;
    }

    /* 成功案例手机端紧凑卡片：一屏内完整可见 */
    .cases-track .case-card {
        flex: 0 0 300px;
        max-width: 300px;
    }
    .cases-track .case-image,
    .cases-track .case-image img {
        height: 150px;
    }
    .cases-track .case-content {
        padding: 14px 16px 16px;
    }
    .cases-track .case-content h3 {
        font-size: 16px;
        margin-bottom: 6px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }
    .cases-track .case-content p {
        font-size: 13px;
        line-height: 1.6;
        margin-bottom: 10px;
        display: -webkit-box;
        -webkit-line-clamp: 2;
        -webkit-box-orient: vertical;
        overflow: hidden;
    }
    .cases-track .case-tags span {
        font-size: 11px;
        padding: 2px 8px;
    }
}

/* ---------- 合作伙伴滚动墙 ---------- */
.partners {
    padding: 80px 0;
    background: #fff;
}
.partners-marquee {
    overflow: hidden;
    position: relative;
    width: 100vw;
    margin-left: calc(50% - 50vw);
    margin-right: 0;
    padding: 0;
    -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 5%, #000 95%, transparent 100%);
    mask-image: linear-gradient(90deg, transparent 0, #000 5%, #000 95%, transparent 100%);
    touch-action: pan-y;
}
.partners-marquee + .partners-marquee {
    margin-top: 18px;
}
.partners-track {
    display: flex;
    gap: 18px;
    width: max-content;
    will-change: transform;
}

.partner-item {
    flex: 0 0 auto;
    width: 170px;
    height: 100px;
    background: #fff;
    border: 1px solid #e8edf3;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    transition: box-shadow 0.3s ease, transform 0.3s ease;
}
.partner-item:hover {
    box-shadow: 0 10px 28px rgba(15, 23, 42, 0.1);
    transform: translateY(-4px);
}
.partner-item img {
    max-width: 88%;
    max-height: 78%;
    object-fit: contain;
    display: block;
    transition: transform 0.3s ease;
}
.partner-item:hover img {
    transform: scale(1.06);
}


/* ===== 页脚友情链接 ===== */
.footer-friends{display:flex;flex-wrap:wrap;align-items:center;gap:6px 18px;padding:18px 0 6px;margin-top:16px;border-top:1px solid rgba(255,255,255,.14)}
.footer-friends .friends-label{color:rgba(255,255,255,.55);font-size:13px}
.footer-friends a{color:rgba(255,255,255,.78);font-size:13px;text-decoration:none;transition:color .15s}
.footer-friends a:hover{color:#fff}

/* 防止首屏 AOS 闪烁：JS 初始化前保持内容可见，初始化后再启用入场动画 */
html:not(.aos-ready) [data-aos]{opacity:1;transform:none;transition:none}