/* ==================== 基础样式与变量 ==================== */
:root {
    /* 颜色系统 - 商务专业浅色主题 */
    --primary-color: #c62828;
    --primary-dark: #8e0000;
    --primary-light: #ff5f52;
    --secondary-color: #f5f5f5;
    --accent-color: #2196F3;
    
    /* 背景色 */
    --bg-light: #ffffff;
    --bg-light-2: #fafafa;
    --bg-light-3: #f5f5f5;
    --bg-light-4: #eeeeee;
    
    /* 文字颜色 */
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-muted: #999999;
    
    /* 边框颜色 */
    --border-color: #e0e0e0;
    --border-light: rgba(0, 0, 0, 0.08);
    
    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-glow: 0 0 20px rgba(198, 40, 40, 0.2);
    
    /* 动画时间 */
    --transition-fast: 0.2s;
    --transition-normal: 0.3s;
    --transition-slow: 0.5s;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ==================== 导航栏 ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    transition: all var(--transition-normal);
    border-bottom: 1px solid transparent;
}

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

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    transition: transform var(--transition-normal);
}

.logo:hover {
    transform: scale(1.05);
}

.logo img {
    height: 50px;
    width: auto;
}

.company-name {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    position: relative;
    padding: 8px 0;
    transition: color var(--transition-normal);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    transition: width var(--transition-normal);
}

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

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

.hamburger {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
    padding: 8px;
}

.hamburger span {
    display: block;
    width: 25px;
    height: 2px;
    background-color: var(--text-secondary);
    transition: all var(--transition-normal);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

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

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

/* ==================== Hero Section ==================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        linear-gradient(135deg, #ffffff 0%, #fafafa 50%, #f5f5f5 100%),
        radial-gradient(circle at 20% 30%, rgba(198, 40, 40, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(33, 150, 243, 0.03) 0%, transparent 50%);
    z-index: -1;
}

.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(90deg, rgba(0,0,0,.02) 1px, transparent 1px),
        linear-gradient(rgba(0,0,0,.02) 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 {
    text-align: center;
    max-width: 900px;
    margin-bottom: 60px;
    animation: fadeInUp 1s ease-out;
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.title-line {
    display: inline-block;
    opacity: 0;
    animation: fadeInUp 0.8s ease-out forwards;
}

.title-line:nth-child(1) {
    animation-delay: 0.2s;
}

.title-line:nth-child(2) {
    animation-delay: 0.4s;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    opacity: 0;
    animation: fadeInUp 0.8s ease-out 0.6s forwards;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    opacity: 0;
    animation: fadeInUp 0.8s ease-out 0.8s forwards;
}

.btn {
    display: inline-block;
    padding: 14px 32px;
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    border-radius: 8px;
    transition: all var(--transition-normal);
    cursor: pointer;
    border: 2px solid transparent;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(198, 40, 40, 0.35);
}

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

.btn-secondary:hover {
    background: rgba(198, 40, 40, 0.05);
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* Hero Stats */
.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    width: 100%;
    max-width: 900px;
    opacity: 0;
    animation: fadeInUp 0.8s ease-out 1s forwards;
}

.stat-item {
    text-align: center;
    padding: 24px;
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid var(--border-light);
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.stat-item:hover {
    transform: translateY(-5px);
    background: #ffffff;
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.stat-number::after {
    content: '+';
}

.stat-label {
    font-size: 14px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.mouse {
    width: 24px;
    height: 38px;
    border: 2px solid var(--text-muted);
    border-radius: 12px;
    position: relative;
}

.wheel {
    width: 3px;
    height: 8px;
    background: var(--primary-color);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: wheelScroll 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(-10px); }
}

@keyframes wheelScroll {
    0% { opacity: 1; top: 8px; }
    100% { opacity: 0; top: 20px; }
}

/* ==================== Section 通用样式 ==================== */
.section {
    padding: 100px 0;
    position: relative;
}

.section-dark {
    background: var(--bg-light-2);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(198, 40, 40, 0.08);
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
    border: 1px solid rgba(198, 40, 40, 0.2);
}

.section-title {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 16px;
}

.title-underline {
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    margin: 0 auto;
    border-radius: 2px;
}

/* ==================== 公司简介 ==================== */
.about-content {
    max-width: 1000px;
    margin: 0 auto;
}

.about-text {
    font-size: 16px;
    line-height: 1.8;
    margin-bottom: 50px;
    text-align: center;
}

.about-intro {
    font-size: 22px;
    margin-bottom: 24px;
    color: var(--text-primary);
    font-weight: 500;
}

.about-text p {
    margin-bottom: 20px;
    color: var(--text-secondary);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.about-text p:last-child {
    margin-bottom: 0;
}

.about-text strong {
    color: var(--primary-color);
    font-weight: 600;
}

.highlight {
    color: var(--primary-color);
    font-weight: 600;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
}

.feature-box {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 32px 24px;
    text-align: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.feature-box:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: white;
    box-shadow: 0 4px 12px rgba(198, 40, 40, 0.25);
}

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

.feature-box h4 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.feature-box p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

.about-image {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    transition: transform var(--transition-slow);
    border: 1px solid var(--border-light);
}

.about-image:hover {
    transform: scale(1.02);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

.about-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* About Page Single Column Layout */
.about-content-single {
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.about-text-centered {
    margin-bottom: 50px;
}

.about-text-centered p {
    text-align: center;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: 16px;
}

.about-text-centered p:last-child {
    margin-bottom: 0;
}

.about-features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.feature-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 30px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.feature-card .feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 32px;
    box-shadow: 0 4px 12px rgba(198, 40, 40, 0.25);
}

.feature-card h3 {
    font-size: 22px;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 15px;
    margin: 0;
}

/* 关于我们独立页 */
.about-page .navbar {
    position: fixed;
}

.about-hero {
    padding-top: 140px;
    text-align: center;
    background: var(--bg-light);
}

.about-hero-subtitle {
    max-width: 760px;
    margin: 16px auto 32px;
    color: var(--text-secondary);
    font-size: 18px;
}

.join-section {
    background: var(--bg-light-2);
}

.join-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.join-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 32px;
    box-shadow: var(--shadow-sm);
}

.join-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
}

.join-card p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.join-list,
.benefit-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.join-list li,
.benefit-list li {
    padding: 16px;
    border-radius: 12px;
    border: 1px dashed var(--border-light);
    background: var(--bg-light-2);
}

.join-list strong {
    display: block;
    font-size: 16px;
    margin-bottom: 6px;
    color: var(--text-primary);
}

.join-list span,
.benefit-list li {
    color: var(--text-secondary);
    font-size: 14px;
}

.benefit-note {
    color: var(--text-secondary);
    font-size: 14px;
}

.join-btn {
    display: inline-block;
    width: 100%;
    text-align: center;
}

/* ==================== 综合能力 ==================== */
.capabilities {
    padding: 80px 0;
}

.capabilities-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-top: 50px;
}

.capability-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 32px;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.capability-card:hover {
    transform: translateY(-5px);
    background: #ffffff;
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.card-wide {
    grid-column: 1 / -1;
}

.card-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: white;
    box-shadow: 0 4px 12px rgba(198, 40, 40, 0.25);
}

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

.capability-card h3 {
    font-size: 24px;
    margin-bottom: 16px;
    color: var(--text-primary);
}

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

/* Tech Tags */
.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.tech-tag {
    display: inline-block;
    padding: 8px 16px;
    background: rgba(198, 40, 40, 0.08);
    color: var(--primary-color);
    border: 1px solid rgba(198, 40, 40, 0.2);
    border-radius: 20px;
    font-size: 14px;
    transition: all var(--transition-normal);
    cursor: default;
}

.tech-tag:hover {
    background: rgba(198, 40, 40, 0.15);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

/* Info Grid */
.info-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.info-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--shadow-sm);
}

.info-card h4 {
    font-size: 20px;
    margin-bottom: 16px;
    color: var(--primary-color);
}

.info-list {
    list-style: none;
}

.info-list li {
    padding: 8px 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 20px;
}

.info-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* ==================== 产品展示图 ==================== */
.product-showcase {
    margin: 50px 0 60px;
    position: relative;
}

.showcase-image {
    position: relative;
    max-width: 1000px;
    margin: 0 auto;
    transition: opacity var(--transition-normal);
}

.showcase-image:hover {
    opacity: 0.95;
}

.showcase-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* ==================== 产品体系 ==================== */
.products-intro {
    font-size: 18px;
    color: var(--text-secondary);
    margin-top: 24px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.8;
    text-align: center;
}

.products-cta {
    text-align: center;
    margin-top: 50px;
}

.products-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 50px;
}

.category-item {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 24px;
    text-align: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
    cursor: pointer;
}

.category-item:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.category-item.featured {
    background: linear-gradient(135deg, rgba(198, 40, 40, 0.05), rgba(255, 255, 255, 1));
    border-color: var(--primary-color);
}

.category-item .category-icon {
    font-size: 36px;
    margin-bottom: 12px;
}

.category-item h3 {
    font-size: 16px;
    color: var(--text-primary);
    font-weight: 600;
    margin: 0;
}

/* ==================== 产品展示页面布局 ==================== */
.products-layout {
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 40px;
    margin-top: 50px;
    align-items: start;
}

.products-sidebar {
    position: sticky;
    top: 100px;
}

.category-nav {
    list-style: none;
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 16px 0;
    box-shadow: var(--shadow-sm);
}

.category-nav li {
    margin: 0;
}

.category-link {
    display: block;
    padding: 12px 24px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 15px;
    transition: all var(--transition-normal);
    border-left: 3px solid transparent;
}

.category-link:hover {
    color: var(--primary-color);
    background: rgba(198, 40, 40, 0.05);
    border-left-color: var(--primary-color);
}

.category-link.active {
    color: var(--primary-color);
    background: rgba(198, 40, 40, 0.08);
    border-left-color: var(--primary-color);
    font-weight: 600;
}

.products-content {
    min-height: 600px;
}

.products-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.product-item {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 24px;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.product-item:hover {
    transform: translateY(-3px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.product-item.featured {
    background: linear-gradient(135deg, rgba(198, 40, 40, 0.03), rgba(255, 255, 255, 1));
    border-color: var(--primary-color);
}

.product-item.hidden {
    display: none;
}

.product-name {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
    line-height: 1.4;
}

.product-desc {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin: 0;
}

/* 产品展示页面的产品网格 */
.products-content .products-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.product-category {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 28px;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.product-category:hover {
    transform: translateY(-5px);
    background: #ffffff;
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.product-category.featured {
    background: linear-gradient(135deg, rgba(198, 40, 40, 0.05), rgba(255, 255, 255, 1));
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.category-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-light);
}

.category-icon {
    font-size: 32px;
}

.category-header h3 {
    font-size: 20px;
    color: var(--text-primary);
}

.product-list {
    list-style: none;
}

.product-list li {
    padding: 10px 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 20px;
    transition: color var(--transition-normal);
}

.product-list li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-size: 20px;
}

.product-list li:hover {
    color: var(--text-primary);
    padding-left: 24px;
}

/* ==================== 解决方案 ==================== */
.solutions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.solution-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 40px;
    text-align: center;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.solution-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

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

.solution-card:hover {
    transform: translateY(-8px);
    background: #ffffff;
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.solution-icon {
    font-size: 64px;
    margin-bottom: 24px;
}

.solution-card h3 {
    font-size: 22px;
    margin-bottom: 16px;
    color: var(--text-primary);
}

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

/* ==================== 下载中心 ==================== */
.downloads {
    background: var(--bg-light);
}

.download-card {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
    padding: 48px;
    border-radius: 20px;
    border: 1px solid var(--border-light);
    background: #ffffff;
    box-shadow: var(--shadow-md);
    align-items: center;
}

.download-info {
    flex: 1 1 55%;
}

.download-details {
    flex: 1 1 35%;
    display: flex;
    flex-direction: column;
    gap: 20px;
    background: var(--bg-light-3);
    border-radius: 16px;
    padding: 32px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
}

.download-badge {
    display: inline-block;
    padding: 6px 14px;
    border-radius: 999px;
    background: rgba(33, 150, 243, 0.12);
    color: var(--accent-color);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
}

.download-info h3 {
    font-size: 32px;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.download-info p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.feature-list {
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 24px;
    background: var(--bg-light-2);
}

.feature-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.feature-list ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.feature-list li {
    padding: 16px;
    border-radius: 12px;
    background: #ffffff;
    border: 1px dashed var(--border-light);
}

.feature-list li span {
    display: block;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.feature-list li small {
    color: var(--text-secondary);
}

.file-meta {
    display: flex;
    flex-direction: column;
    gap: 6px;
    color: var(--text-secondary);
    font-size: 15px;
}

/* ==================== 核心功能表格 ==================== */
.core-features {
    padding: 80px 0;
}

.features-table-container {
    margin-top: 50px;
    overflow-x: auto;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    background: #ffffff;
}

.features-table {
    width: 100%;
    border-collapse: collapse;
    background: #ffffff;
}

.features-table thead {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: #ffffff;
}

.features-table th {
    padding: 20px;
    text-align: left;
    font-weight: 600;
    font-size: 16px;
    border-bottom: 2px solid rgba(255, 255, 255, 0.2);
}

.features-table th.col-feature {
    width: 15%;
    min-width: 120px;
}

.features-table th.col-description {
    width: 45%;
    min-width: 300px;
}

.features-table th.col-demo {
    width: 40%;
    min-width: 250px;
    text-align: center;
}

.features-table tbody tr {
    border-bottom: 1px solid var(--border-light);
    transition: background-color var(--transition-normal);
}

.features-table tbody tr:hover {
    background: var(--bg-light-2);
}

.features-table tbody tr:last-child {
    border-bottom: none;
}

.features-table td {
    padding: 24px 20px;
    vertical-align: top;
}

.feature-name {
    font-weight: 600;
    font-size: 18px;
    color: var(--text-primary);
    white-space: nowrap;
}

.feature-desc {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.8;
}

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

.demo-gif {
    max-width: 100%;
    height: auto;
    max-height: 200px;
    border-radius: 8px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

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

/* 功能表格响应式 */
@media (max-width: 1024px) {
    .features-table th.col-feature {
        width: 18%;
    }
    
    .features-table th.col-description {
        width: 42%;
    }
    
    .features-table th.col-demo {
        width: 40%;
    }
}

@media (max-width: 768px) {
    .core-features {
        padding: 60px 0;
    }
    
    .features-table-container {
        margin-top: 40px;
    }
    
    .features-table {
        font-size: 14px;
    }
    
    .features-table th {
        padding: 16px 12px;
        font-size: 14px;
    }
    
    .features-table td {
        padding: 20px 12px;
    }
    
    .feature-name {
        font-size: 16px;
    }
    
    .feature-desc {
        font-size: 14px;
        line-height: 1.6;
    }
    
    .demo-gif {
        max-height: 150px;
    }
}

@media (max-width: 480px) {
    .features-table-container {
        border-radius: 12px;
    }
    
    .features-table thead {
        display: none;
    }
    
    .features-table tbody tr {
        display: block;
        margin-bottom: 24px;
        border: 1px solid var(--border-light);
        border-radius: 12px;
        padding: 16px;
        background: #ffffff;
    }
    
    .features-table tbody tr:last-child {
        margin-bottom: 0;
    }
    
    .features-table td {
        display: block;
        padding: 12px 0;
        border: none;
        text-align: left;
    }
    
    .features-table td:before {
        content: attr(data-label);
        font-weight: 600;
        color: var(--primary-color);
        display: block;
        margin-bottom: 8px;
        font-size: 14px;
    }
    
    .feature-name {
        font-size: 18px;
        margin-bottom: 12px;
        padding-bottom: 12px;
        border-bottom: 2px solid var(--primary-color);
    }
    
    .feature-demo {
        text-align: center;
        margin-top: 16px;
    }
    
    .demo-gif {
        max-height: 180px;
        width: 100%;
    }
}

.download-tip {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 独立下载页 */
.download-page {
    background: var(--bg-light);
}

.download-hero {
    padding-top: 140px;
    text-align: center;
}

.xiaoxue-logo-container {
    margin-bottom: 30px;
}

.xiaoxue-logo {
    width: 180px;
    height: auto;
    display: block;
    margin: 0 auto;
    filter: drop-shadow(0 4px 12px rgba(198, 40, 40, 0.2));
}

.download-hero-subtitle {
    max-width: 720px;
    margin: 16px auto 24px;
    color: var(--text-secondary);
    font-size: 18px;
}

/* ==================== 解决方案独立页布局 ==================== */
.solutions-page main {
    padding-top: 100px; /* Adjust for fixed navbar */
}

.solutions-hero {
    padding: 80px 0;
    text-align: center;
    background: var(--bg-light-2);
    border-bottom: 1px solid var(--border-color);
}

.solutions-hero-subtitle {
    max-width: 800px;
    margin: 16px auto 0;
    color: var(--text-secondary);
    font-size: 18px;
    line-height: 1.8;
}

/* ==================== CAD二次开发独立页布局 ==================== */
.cad-development-page main {
    padding-top: 100px; /* Adjust for fixed navbar */
}

.cad-hero {
    position: relative;
    padding: 80px 0;
    text-align: center;
    background: var(--bg-light-2);
    border-bottom: 1px solid var(--border-color);
    overflow: hidden;
}

.cad-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(135deg, rgba(198, 40, 40, 0.03) 0%, rgba(33, 150, 243, 0.02) 100%),
        url('../images/cad-screens.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0.25;
    z-index: 0;
    filter: grayscale(20%) brightness(1.1);
}

.cad-hero::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 30%, rgba(255, 255, 255, 0.9) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(250, 250, 250, 0.8) 0%, transparent 50%),
        linear-gradient(135deg, rgba(255, 255, 255, 0.75) 0%, rgba(250, 250, 250, 0.85) 100%);
    z-index: 1;
}

.cad-hero .container {
    position: relative;
    z-index: 2;
}

.cad-hero-subtitle {
    max-width: 800px;
    margin: 16px auto 0;
    color: var(--text-secondary);
    font-size: 18px;
    line-height: 1.8;
}

.cad-services {
    padding: 80px 0;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.service-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 35px;
    text-align: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.service-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.service-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.service-card h3 {
    font-size: 22px;
    color: var(--text-primary);
    margin-bottom: 15px;
}

.service-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 15px;
}

.cad-advantages {
    padding: 80px 0;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.advantage-item {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 30px;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.advantage-item:hover {
    background: #ffffff;
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.advantage-item h3 {
    font-size: 20px;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.advantage-item p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 15px;
}

.cad-value {
    padding: 80px 0;
}

.value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

/* 确保8个卡片时保持对齐 */
@media (min-width: 1200px) {
    .value-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

.value-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 35px;
    text-align: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.value-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.value-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.value-card h3 {
    font-size: 22px;
    color: var(--text-primary);
    margin-bottom: 15px;
}

.value-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 15px;
}

.cad-scenarios {
    padding: 80px 0;
}

.scenarios-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 50px;
}

.scenario-item {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 30px;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.scenario-item:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.scenario-item h3 {
    font-size: 20px;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.scenario-item p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 15px;
}

/* ==================== 客户案例独立页布局 ==================== */
.customer-cases-page main {
    padding-top: 100px; /* Adjust for fixed navbar */
}

.cases-hero {
    padding: 80px 0;
    text-align: center;
    background: var(--bg-light-2);
    border-bottom: 1px solid var(--border-color);
}

.cases-hero-subtitle {
    max-width: 800px;
    margin: 16px auto 0;
    color: var(--text-secondary);
    font-size: 18px;
    line-height: 1.8;
}

.cases {
    padding: 80px 0;
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.case-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 35px;
    text-align: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.case-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.case-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.case-card h3 {
    font-size: 24px;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.case-category {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(198, 40, 40, 0.1);
    color: var(--primary-color);
    border-radius: 12px;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 15px;
}

.case-description {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 15px;
}

.cases-stats {
    padding: 80px 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.stat-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 35px;
    text-align: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.stat-card:hover {
    background: #ffffff;
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.stat-card .stat-number {
    font-size: 42px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.stat-card .stat-label {
    font-size: 18px;
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 10px;
}

.stat-card p {
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 14px;
    margin-top: 8px;
}

.cases-industries {
    padding: 80px 0;
}

.industries-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 50px;
}

.industry-item {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 30px;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.industry-item:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.industry-item h3 {
    font-size: 20px;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.industry-item p {
    color: var(--text-secondary);
    line-height: 1.7;
    font-size: 15px;
}

.name-origin {
    max-width: 720px;
    margin: 0 auto 32px;
    padding: 16px 24px;
    background: rgba(198, 40, 40, 0.05);
    border-left: 4px solid var(--primary-color);
    border-radius: 8px;
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.8;
    font-style: italic;
}

.download-meta-grid {
    margin-top: 40px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
}

.meta-card {
    padding: 20px;
    border-radius: 12px;
    border: 1px solid var(--border-light);
    background: #ffffff;
    box-shadow: var(--shadow-sm);
}

.meta-label {
    font-size: 14px;
    color: var(--text-muted);
    display: block;
    margin-bottom: 6px;
}

.step-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
}

.step-card {
    border-radius: 16px;
    border: 1px solid var(--border-light);
    padding: 32px;
    background: #ffffff;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.step-card::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 16px;
    border: 2px solid transparent;
    background: linear-gradient(120deg, rgba(198, 40, 40, 0.1), rgba(255, 255, 255, 0));
    pointer-events: none;
}

.step-index {
    font-size: 36px;
    font-weight: 700;
    color: var(--primary-color);
    display: block;
    margin-bottom: 12px;
}

.step-card h3 {
    margin-bottom: 10px;
}

.download-support .support-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
}

.support-card {
    background: #ffffff;
    border-radius: 16px;
    padding: 28px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.support-card h3 {
    margin-bottom: 12px;
}

.support-contact {
    margin-top: 32px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 16px;
}

/* ==================== 合作伙伴 ==================== */
.partners-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 32px;
}

.partner-card {
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 40px 24px;
    text-align: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.partner-card:hover {
    transform: translateY(-5px) scale(1.02);
    background: #ffffff;
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.partner-logo {
    font-size: 64px;
    margin-bottom: 20px;
}

.partner-card h4 {
    font-size: 18px;
    color: var(--text-primary);
}

/* ==================== 联系我们 ==================== */
.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info {
    display: grid;
    gap: 32px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 24px;
    padding: 32px;
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: 12px;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.contact-item:hover {
    transform: translateX(5px);
    background: #ffffff;
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: white;
    box-shadow: 0 4px 12px rgba(198, 40, 40, 0.25);
}

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

.contact-details h4 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.contact-details p {
    font-size: 16px;
    color: var(--text-secondary);
}

/* 二维码样式 */
.contact-qrcode {
    margin-top: 20px;
    text-align: center;
}

.qrcode-image {
    max-width: 150px;
    max-height: 150px;
    width: auto;
    height: auto;
    border: 1px solid var(--border-light);
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
    display: block;
    margin: 0 auto 10px;
    background: #ffffff;
}

.qrcode-label {
    font-size: 14px;
    color: var(--text-muted);
    margin: 0;
}

.footer-qrcode {
    margin-top: 16px;
    text-align: center;
}

.qrcode-image-small {
    max-width: 100px;
    max-height: 100px;
    width: auto;
    height: auto;
    border: 1px solid var(--border-light);
    border-radius: 6px;
    box-shadow: var(--shadow-sm);
    display: block;
    margin: 0 auto;
    background: #ffffff;
}

/* 二维码响应式样式 */
@media (max-width: 768px) {
    .qrcode-image {
        width: 120px;
        height: 120px;
    }
    
    .qrcode-image-small {
        width: 80px;
        height: 80px;
    }
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--bg-light-3);
    border-top: 1px solid var(--border-color);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.footer-logo img {
    width: 60px;
    height: auto;
}

.footer-logo p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-top: 8px;
}

.footer-links h4,
.footer-contact h4 {
    font-size: 18px;
    margin-bottom: 16px;
    color: var(--text-primary);
}

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

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-normal);
}

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

.footer-contact p {
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-size: 14px;
}

.footer-bottom {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: space-between;
    align-items: center;
    text-align: left;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 14px;
    margin: 0;
}

/* ==================== 固定客户经理联系方式 ==================== */
.fixed-contact {
    position: fixed;
    top: 50%;
    right: 30px;
    transform: translateY(-50%);
    z-index: 998;
    font-family: inherit;
}

.fixed-contact-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 14px 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 4px 20px rgba(198, 40, 40, 0.3);
    transition: all var(--transition-normal);
    font-size: 15px;
    font-weight: 600;
}

.fixed-contact-toggle:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 25px rgba(198, 40, 40, 0.4);
}

.fixed-contact-toggle .contact-icon {
    font-size: 20px;
}

.fixed-contact-card {
    position: relative;
    width: 280px;
    background: #ffffff;
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    overflow: hidden;
}

.fixed-contact-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
}

.fixed-contact-header h4 {
    margin: 0;
    font-size: 18px;
    font-weight: 600;
}

.fixed-contact-close {
    background: none;
    border: none;
    color: white;
    font-size: 28px;
    line-height: 1;
    cursor: pointer;
    padding: 0;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all var(--transition-normal);
}

.fixed-contact-close:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: rotate(90deg);
}

.fixed-contact-content {
    padding: 20px;
}

.fixed-contact-info {
    margin-bottom: 20px;
}

.fixed-contact-item {
    margin-bottom: 16px;
}

.fixed-contact-item:last-child {
    margin-bottom: 0;
}

.fixed-contact-label {
    display: block;
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 6px;
}

.fixed-contact-value {
    display: block;
    font-size: 16px;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 600;
    transition: color var(--transition-normal);
}

.fixed-contact-value:hover {
    color: var(--primary-color);
}

.fixed-contact-qrcode {
    text-align: center;
    padding-top: 16px;
    border-top: 1px solid var(--border-light);
}

.fixed-qrcode-image {
    width: 140px;
    height: 140px;
    border: 1px solid var(--border-light);
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
    margin: 0 auto 10px;
    display: block;
}

.fixed-qrcode-label {
    font-size: 13px;
    color: var(--text-muted);
    margin: 0;
}

/* ==================== 返回顶部按钮 ==================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 999;
    box-shadow: 0 4px 20px rgba(198, 40, 40, 0.3);
}

/* 调整返回顶部按钮位置，避免与固定联系方式重叠 */
.cad-development-page .back-to-top {
    bottom: 30px;
    right: 30px;
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 25px rgba(198, 40, 40, 0.4);
}

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

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

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 48px;
    }
    
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    
    .about-content {
        max-width: 100%;
    }

    .about-features {
        grid-template-columns: 1fr;
        gap: 24px;
        margin-top: 40px;
    }

    .about-features-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .feature-box {
        padding: 28px 20px;
    }

    .feature-card {
        padding: 24px;
    }

    .about-content-single {
        text-align: left;
    }

    .about-text-centered p {
        text-align: left;
    }
    
    .capabilities-grid {
        grid-template-columns: 1fr;
    }
    
    .info-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .about-hero {
        padding-top: 120px;
    }

    .download-hero {
        padding-top: 120px;
    }

    .solutions-hero {
        padding: 60px 0;
    }

    .solutions-hero-subtitle {
        font-size: 16px;
    }

    .cad-hero {
        padding: 60px 0;
    }

    .cad-hero {
        padding: 60px 0;
    }
    
    .cad-hero::before {
        opacity: 0.18;
        filter: grayscale(30%) brightness(1.15);
    }
    
    .cad-hero::after {
        background: 
            radial-gradient(circle at 20% 30%, rgba(255, 255, 255, 0.95) 0%, transparent 50%),
            linear-gradient(135deg, rgba(255, 255, 255, 0.88) 0%, rgba(250, 250, 250, 0.92) 100%);
    }

    .cad-hero-subtitle {
        font-size: 16px;
    }

    .cad-services,
    .cad-advantages,
    .cad-value,
    .cad-scenarios {
        padding: 60px 0;
    }

    .capabilities {
        padding: 60px 0;
    }

    .services-grid,
    .advantages-grid,
    .value-grid {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 24px;
    }

    .scenarios-list {
        grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
        gap: 20px;
    }

    .cases-hero {
        padding: 60px 0;
    }

    .cases-hero-subtitle {
        font-size: 16px;
    }

    .cases,
    .cases-stats,
    .cases-industries {
        padding: 60px 0;
    }

    .cases-grid,
    .stats-grid,
    .industries-list {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 24px;
    }

    .xiaoxue-logo {
        width: 150px;
    }

    .download-meta-grid {
        grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    }

    .download-card {
        padding: 40px;
    }

    .download-details {
        padding: 28px;
    }

    .products-layout {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .products-sidebar {
        position: static;
    }

    .category-nav {
        display: flex;
        flex-wrap: wrap;
        gap: 8px;
        padding: 16px;
    }

    .category-nav li {
        flex: 1 1 auto;
    }

    .category-link {
        padding: 10px 16px;
        border-left: none;
        border-bottom: 3px solid transparent;
        text-align: center;
        border-radius: 8px;
    }

    .category-link.active {
        border-left: none;
        border-bottom-color: var(--primary-color);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 82px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(10px);
        padding: 24px;
        gap: 16px;
        transform: translateX(-100%);
        transition: transform var(--transition-normal);
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero {
        padding: 100px 0 60px;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .products-categories {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: 16px;
        margin-top: 40px;
    }

    .category-item {
        padding: 20px;
    }

    .category-item .category-icon {
        font-size: 32px;
    }

    .category-item h3 {
        font-size: 14px;
    }

    .about-text {
        text-align: left;
    }

    .about-text p {
        max-width: 100%;
    }

    .about-features {
        grid-template-columns: 1fr;
        gap: 20px;
        margin-top: 40px;
    }

    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .solutions-grid {
        grid-template-columns: 1fr;
    }
    
    .partners-grid {
        grid-template-columns: 1fr;
    }

    .download-meta-grid,
    .step-grid,
    .download-support .support-grid {
        grid-template-columns: 1fr;
    }

    .step-card {
        padding: 24px;
    }

    .download-card {
        flex-direction: column;
        padding: 28px;
    }

    .download-info,
    .download-details {
        flex: 1 1 100%;
    }

    .download-info h3 {
        font-size: 28px;
    }

    .product-showcase {
        margin: 40px 0 40px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .stat-number {
        font-size: 36px;
    }

    .download-hero-subtitle {
        font-size: 16px;
        margin-bottom: 24px;
    }

    .solutions-hero {
        padding: 40px 0;
    }

    .solutions-hero-subtitle {
        font-size: 14px;
    }

    .cad-hero {
        padding: 40px 0;
    }
    
    .cad-hero::before {
        opacity: 0.12;
        background-size: contain;
        filter: grayscale(40%) brightness(1.2);
    }
    
    .cad-hero::after {
        background: 
            radial-gradient(circle at center, rgba(255, 255, 255, 0.98) 0%, transparent 70%),
            linear-gradient(135deg, rgba(255, 255, 255, 0.92) 0%, rgba(250, 250, 250, 0.96) 100%);
    }

    .cad-hero-subtitle {
        font-size: 14px;
    }

    .cad-services,
    .cad-advantages,
    .cad-value,
    .cad-scenarios {
        padding: 40px 0;
    }

    .capabilities {
        padding: 40px 0;
    }

    .services-grid,
    .advantages-grid,
    .value-grid,
    .scenarios-list {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .service-card,
    .advantage-item,
    .value-card,
    .scenario-item {
        padding: 24px;
    }

    .cases-hero {
        padding: 40px 0;
    }

    .cases-hero-subtitle {
        font-size: 14px;
    }

    .cases,
    .cases-stats,
    .cases-industries {
        padding: 40px 0;
    }

    .cases-grid,
    .stats-grid,
    .industries-list {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .case-card,
    .stat-card,
    .industry-item {
        padding: 24px;
    }

    .case-card h3 {
        font-size: 20px;
    }

    .stat-card .stat-number {
        font-size: 36px;
    }

    .name-origin {
        font-size: 13px;
        padding: 14px 20px;
        margin-bottom: 28px;
    }

    .xiaoxue-logo {
        width: 120px;
    }

    .products-categories {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
        margin-top: 30px;
    }

    .category-item {
        padding: 16px;
    }

    .category-item .category-icon {
        font-size: 28px;
        margin-bottom: 8px;
    }

    .category-item h3 {
        font-size: 13px;
    }

    .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .back-to-top {
        width: 45px;
        height: 45px;
        bottom: 20px;
        right: 20px;
    }

    .download-card {
        padding: 24px;
    }
    
    .fixed-contact {
        top: 50%;
        right: 20px;
        transform: translateY(-50%);
    }
    
    .fixed-contact-card {
        width: calc(100vw - 40px);
        max-width: 280px;
    }

    .download-details {
        padding: 20px;
    }

    .products-layout {
        gap: 20px;
    }

    .category-nav {
        padding: 12px;
    }

    .category-link {
        padding: 8px 12px;
        font-size: 14px;
    }

    .product-item {
        padding: 20px;
    }

    .product-name {
        font-size: 16px;
    }

    .product-desc {
        font-size: 13px;
    }

    .product-showcase {
        margin: 30px 0 30px;
    }
}