:root {
    --primary: #2B5AED;
    --primary-light: #4B7BFF;
    --primary-dark: #1A3FA0;
    --secondary: #00D6C9;
    --dark: #1A1F3D;
    --gray: #6B7280;
    --light: #F5F7FA;
    --white: #FFFFFF;
    
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    
    --transition: all 0.3s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background: var(--white);
    overflow-x: hidden;
}

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

/* 主要内容区域 */
.download-main {
    min-height: calc(100vh - 180px);
    padding: 120px 0;
    background: var(--light);
}

/* 标签导航 */
.tab-nav {
    background: var(--white);
    padding: 20px 0;
    margin-bottom: 40px;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.tab-list {
    display: flex;
    gap: 20px;
    justify-content: center;
}

.tab-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 16px 24px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    color: var(--gray);
}

.tab-item i {
    font-size: 24px;
}

.tab-item span {
    font-size: 16px;
}

.tab-item.active {
    background: var(--primary);
    color: var(--white);
}

.tab-item:hover:not(.active) {
    background: var(--light);
    color: var(--primary);
}

/* 内容区域 */
.content-wrapper {
    padding: 40px 0;
}

.content-block {
    display: none;
    animation: fadeIn 0.3s ease;
}

.content-block.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 产品展示区 */
.product-showcase {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    background: var(--white);
    padding: 40px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.showcase-info h1,
.showcase-info h2 {
    font-size: 36px;
    margin-bottom: 16px;
    color: var(--dark);
}

.subtitle {
    font-size: 18px;
    color: var(--gray);
    margin-bottom: 32px;
}

.feature-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 32px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 12px;
}

.feature-item i {
    color: var(--primary);
    font-size: 20px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 16px 32px;
    background: var(--primary);
    color: var(--white);
    border: none;
    border-radius: var(--radius-md);
    font-size: 16px;
    cursor: pointer;
    transition: var(--transition);
}

.download-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.showcase-preview {
    position: relative;
}

.preview-img {
    width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
}

.preview-img:hover {
    transform: scale(1.02);
}

/* 小程序区域 */
.miniapp-section {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
    max-width: 800px;
    margin: 0 auto;
}

.miniapp-card {
    background: var(--white);
    padding: 40px;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

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

.miniapp-card h3 {
    font-size: 24px;
    margin-bottom: 16px;
}

.miniapp-card p {
    color: var(--gray);
    margin-bottom: 24px;
}

.qrcode-box {
    width: 200px;
    height: 200px;
    margin: 0 auto;
}

.qrcode-box img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

/* 手册和文档区域 */
.manual-section,
.docs-section {
    display: grid;
    gap: 30px;
    max-width: 800px;
    margin: 0 auto;
}

.manual-card,
.doc-card {
    display: flex;
    gap: 24px;
    background: var(--white);
    padding: 24px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.manual-card:hover,
.doc-card:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.manual-icon,
.doc-icon {
    width: 80px;
    height: 80px;
    flex-shrink: 0;
}

.manual-icon img,
.doc-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius-sm);
}

.manual-info,
.doc-info {
    flex: 1;
}

.manual-info h3,
.doc-info h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.manual-info p,
.doc-info p {
    font-size: 14px;
    color: var(--gray);
    margin-bottom: 16px;
}

.download-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--primary);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

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

/* 响应式设计 */
@media (max-width: 1024px) {
    .product-showcase {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 30px;
    }

    .feature-list {
        display: inline-flex;
        flex-direction: column;
        align-items: flex-start;
        text-align: left;
    }

    .showcase-preview {
        order: -1;
    }

    .preview-img {
        max-width: 500px;
        margin: 0 auto;
    }
}

@media (max-width: 768px) {
    .tab-list {
        overflow-x: auto;
        padding-bottom: 10px;
        -webkit-overflow-scrolling: touch;
        justify-content: flex-start;
    }

    .tab-item {
        flex: 0 0 auto;
        min-width: 120px;
    }

    .miniapp-section {
        grid-template-columns: 1fr;
    }

    .manual-card,
    .doc-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .manual-icon,
    .doc-icon {
        width: 100px;
        height: 100px;
    }
}

@media (max-width: 480px) {
    .download-main {
        padding: 20px 0;
    }

    .tab-item {
        padding: 12px 16px;
    }

    .tab-item i {
        font-size: 20px;
    }

    .tab-item span {
        font-size: 14px;
    }

    .showcase-info h1,
    .showcase-info h2 {
        font-size: 28px;
    }

    .subtitle {
        font-size: 16px;
    }

    .download-btn {
        width: 100%;
    }
}

/* 暗色模式 */
@media (prefers-color-scheme: dark) {
    :root {
        --white: #1A1F3D;
        --light: #2A2F4D;
        --dark: #F3F4F6;
        --gray: #9CA3AF;
    }
}

/* 性能优化 */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}