:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --accent-purple: #7c3aed;
    --gradient-main: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --bg-dark: #0f172a;
    --bg-dark-card: #1e293b;
    --text-heading: #0f172a;
    --text-body: #475569;
    --text-muted: #64748b;
    --border-light: #e2e8f0;
    --border-dark: #334155;
    --radius-xl: 20px;
    --radius-lg: 12px;
    --radius-md: 8px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

html { 
    scroll-behavior: smooth; 
}

body {
    font-family: 'Plus Jakarta Sans', 'Noto Sans SC', sans-serif;
    color: var(--text-body);
    background-color: var(--bg-light);
    line-height: 1.6;
    overflow-x: hidden;
}

/* 顶部导航栏（已对齐至 1280px 版心） */
        .navbar {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.85);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--border-light);
            padding: 16px 24px;
            width: 100%;
        }
        .nav-container {
            max-width: 1280px;
            width: 100%;
            margin: 0 auto;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 20px;
        }
        .nav-brand {
            display: flex;
            align-items: center;
            gap: 12px;
            text-decoration: none;
            font-weight: 800;
            font-size: 20px;
            color: var(--text-heading);
            white-space: nowrap;
            flex-shrink: 0;
        }
        /* Logo 图片样式适配 */
        .nav-brand img.logo-img {
            width: 38px;
            height: 38px;
            object-fit: contain;
            border-radius: 8px;
        }
        .nav-links {
            display: flex;
            align-items: center;
            gap: 24px;
            list-style: none;
            margin: 0;
            padding: 0;
        }
        .nav-links a {
            text-decoration: none;
            color: var(--text-body);
            font-weight: 600;
            font-size: 15px;
            white-space: nowrap;
            transition: color 0.2s;
        }
        .nav-links a:hover { color: var(--primary); }
        .nav-right {
            display: flex;
            align-items: center;
            gap: 16px;
            white-space: nowrap;
            flex-shrink: 0;
        }
        .lang-select {
            padding: 6px 12px;
            border-radius: var(--radius-md);
            border: 1px solid var(--border-light);
            background: var(--bg-white);
            font-size: 13px;
            font-weight: 500;
            color: var(--text-heading);
            cursor: pointer;
        }

        /* Canvas 背景 */
        #particle-canvas {
            position: absolute;
            top: 0; left: 0; width: 100%; height: 100%;
            z-index: 0; pointer-events: none; opacity: 0.5;
        }

.lang-select {
    padding: 6px 12px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
    background: var(--bg-white);
    font-size: 13px;
    font-weight: 500;
    color: var(--text-heading);
    cursor: pointer;
}

/* ==========================================================================
   通用按钮与全局画布
   ========================================================================== */
#particle-canvas {
    position: absolute;
    top: 0; 
    left: 0; 
    width: 100%; 
    height: 100%;
    z-index: 0; 
    pointer-events: none; 
    opacity: 0.5;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 30px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 15px;
    text-decoration: none;
    transition: all 0.25s ease;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--gradient-main);
    color: #fff;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 20px -5px rgba(37, 99, 235, 0.4);
}

.btn-secondary {
    background: var(--bg-white);
    color: var(--text-heading);
    border: 1px solid var(--border-light);
}

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

/* 章节通用标题头 */
.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 50px;
}

.section-tag {
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--primary);
    margin-bottom: 8px;
    display: block;
}

.section-title {
    font-size: 36px;
    font-weight: 800;
    color: var(--text-heading);
    line-height: 1.25;
    margin-bottom: 12px;
}

.section-desc {
    font-size: 16px;
    color: var(--text-body);
}

/* ==========================================================================
   Hero 首屏区
   ========================================================================== */
.hero-section {
    position: relative;
    padding: 100px 24px 70px;
    max-width: 1280px;
    width: 100%;
    margin: 0 auto;
    text-align: center;
    z-index: 1;
}

.hero-pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    background: rgba(37, 99, 235, 0.08);
    border: 1px solid rgba(37, 99, 235, 0.2);
    border-radius: 999px;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 24px;
}

.hero-title {
    font-size: 54px;
    font-weight: 800;
    color: var(--text-heading);
    letter-spacing: -0.02em;
    line-height: 1.15;
    margin-bottom: 24px;
}

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

.hero-desc {
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto 36px;
    color: var(--text-body);
}

.hero-btns {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

/* ==========================================================================
   核心统计数据横幅
   ========================================================================== */
.stats-banner {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto 80px;
    padding: 0 24px;
}

.stats-grid {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 32px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 24px;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.stat-value {
    font-size: 36px;
    font-weight: 800;
    color: var(--text-heading);
}

.stat-value span { 
    color: var(--primary); 
}

.stat-label {
    font-size: 14px;
    color: var(--text-muted);
    margin-top: 4px;
    font-weight: 500;
}

/* ==========================================================================
   功能矩阵 (Bento Box)
   ========================================================================== */
.features-section {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto 100px;
    padding: 0 24px;
}

.bento-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.bento-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 32px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.bento-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(37, 99, 235, 0.3);
}

.bento-card.span-2 { 
    grid-column: span 2; 
}

.card-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    margin-bottom: 20px;
}

.bento-card h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-heading);
    margin-bottom: 12px;
}

.bento-card p {
    font-size: 15px;
    color: var(--text-body);
    line-height: 1.6;
}

.card-tags {
    display: flex;
    gap: 8px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.card-tag {
    font-size: 12px;
    padding: 4px 10px;
    border-radius: 6px;
    background: var(--bg-light);
    color: var(--text-muted);
    font-weight: 600;
}

/* ==========================================================================
   多平台下载选项卡
   ========================================================================== */
.download-section {
    background: #ffffff;
    border-top: 1px solid var(--border-light);
    border-bottom: 1px solid var(--border-light);
    padding: 90px 24px;
    margin-bottom: 100px;
}

.download-container {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto;
}

.tab-nav {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 12px 24px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
    background: var(--bg-light);
    font-size: 15px;
    font-weight: 600;
    color: var(--text-body);
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 8px;
}

.tab-btn.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
}

.tab-panel {
    display: none;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
    animation: fadeIn 0.4s ease-in-out;
}

.tab-panel.active { 
    display: grid; 
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.dl-main-card {
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 36px;
}

.version-badge {
    display: inline-block;
    font-size: 12px;
    padding: 4px 10px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    border-radius: 6px;
    font-weight: 700;
    margin-bottom: 16px;
}

.dl-btn-group {
    display: flex;
    gap: 16px;
    margin-top: 28px;
    flex-wrap: wrap;
}

.dl-item-btn {
    flex: 1;
    min-width: 240px;
    padding: 16px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-light);
    background: var(--bg-white);
    text-decoration: none;
    color: var(--text-heading);
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: all 0.2s;
}

.dl-item-btn:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
}

.dl-item-title { 
    font-weight: 700; 
    font-size: 15px; 
}

.dl-item-sub { 
    font-size: 12px; 
    color: var(--text-muted); 
}

.dl-side-card {
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* ==========================================================================
   协议兼容展示（暗色深色区）
   ========================================================================== */
.protocols-dark-wrap {
    background: var(--bg-dark);
    color: #fff;
    padding: 90px 24px;
    margin-bottom: 100px;
}

.protocols-grid {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.proto-box {
    background: var(--bg-dark-card);
    border: 1px solid var(--border-dark);
    border-radius: var(--radius-lg);
    padding: 24px;
}

.proto-box h4 {
    font-size: 18px;
    color: #38bdf8;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.proto-box p { 
    font-size: 14px; 
    color: #94a3b8; 
}

.proto-status {
    font-size: 11px;
    padding: 2px 8px;
    border-radius: 4px;
    background: rgba(56, 189, 248, 0.15);
    color: #38bdf8;
}

/* ==========================================================================
   4 步骤快速配置
   ========================================================================== */
.steps-section {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto 100px;
    padding: 0 24px;
}

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

.step-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 28px;
    position: relative;
}

.step-num {
    width: 36px;
    height: 36px;
    background: var(--gradient-main);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    margin-bottom: 16px;
}

/* ==========================================================================
   横向对比表格
   ========================================================================== */
.compare-section {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto 100px;
    padding: 0 24px;
}

.table-responsive {
    overflow-x: auto;
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
}

.compare-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
    font-size: 15px;
}

.compare-table th, 
.compare-table td {
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-light);
}

.compare-table th {
    background: var(--bg-light);
    color: var(--text-heading);
    font-weight: 700;
}

.compare-table tr:last-child td { 
    border-bottom: none; 
}

.text-check { 
    color: #16a34a; 
    font-weight: bold; 
}

.text-cross { 
    color: #dc2626; 
    font-weight: bold; 
}

/* ==========================================================================
   代码预览区
   ========================================================================== */
.code-section {
    background: var(--bg-dark);
    color: #fff;
    padding: 80px 24px;
    margin-bottom: 100px;
}

.code-container {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

.code-block {
    background: #020617;
    border: 1px solid var(--border-dark);
    border-radius: var(--radius-lg);
    padding: 20px;
    font-family: monospace;
    font-size: 13px;
    color: #e2e8f0;
    overflow-x: auto;
}

/* ==========================================================================
   动态资讯网格（2行 × 3列）
   ========================================================================== */
.news-section {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto 100px;
    padding: 0 24px;
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.news-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 28px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
}

.news-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(37, 99, 235, 0.3);
}

.news-tag {
    display: inline-block;
    font-size: 12px;
    font-weight: 700;
    color: var(--primary);
    background: rgba(37, 99, 235, 0.08);
    padding: 4px 10px;
    border-radius: 6px;
    align-self: flex-start;
    margin-bottom: 16px;
}

.news-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-heading);
    margin-bottom: 10px;
    line-height: 1.4;
}

.news-desc {
    font-size: 14px;
    color: var(--text-body);
    line-height: 1.6;
    margin-bottom: 20px;
    flex-grow: 1;
}

.news-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 12px;
    color: var(--text-muted);
    border-top: 1px solid var(--border-light);
    padding-top: 16px;
}

/* ==========================================================================
   常见问题 FAQ 手风琴
   ========================================================================== */
.faq-section {
    max-width: 900px;
    width: 100%;
    margin: 0 auto 100px;
    padding: 0 24px;
}

.faq-item {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    margin-bottom: 16px;
    overflow: hidden;
}

.faq-question {
    padding: 20px 24px;
    font-weight: 700;
    color: var(--text-heading);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
}

.faq-answer {
    padding: 0 24px 20px;
    font-size: 15px;
    color: var(--text-body);
    display: none;
    border-top: 1px solid var(--bg-light);
    padding-top: 16px;
}

.faq-item.open .faq-answer { 
    display: block; 
}

.faq-item.open .faq-question i { 
    transform: rotate(180deg); 
}

/* ==========================================================================
   CTA 横幅
   ========================================================================== */
.cta-banner {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto 100px;
    padding: 0 24px;
}

.cta-inner {
    background: var(--gradient-main);
    border-radius: var(--radius-xl);
    padding: 60px 40px;
    color: #fff;
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.cta-inner h2 { 
    font-size: 36px; 
    font-weight: 800; 
    margin-bottom: 16px; 
}

.cta-inner p { 
    font-size: 18px; 
    opacity: 0.9; 
    margin-bottom: 32px; 
}

/* ==========================================================================
   页脚 Footer（与 Header 对齐修复）
   ========================================================================== */
.site-footer {
    background: var(--bg-dark);
    color: #94a3b8;
    padding: 80px 24px 40px;
    border-top: 1px solid var(--border-dark);
    font-size: 14px;
}

.footer-container {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto 60px;
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: 40px;
}

.footer-brand h3 {
    color: #fff;
    font-size: 20px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-col h4 {
    color: #fff;
    font-size: 15px;
    font-weight: 700;
    margin-bottom: 16px;
}

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

.footer-col ul li { 
    margin-bottom: 10px; 
}

.footer-col ul a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.2s;
}

.footer-col ul a:hover { 
    color: #fff; 
}

.footer-bottom {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto;
    padding-top: 30px;
    border-top: 1px solid var(--border-dark);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

/* ==========================================================================
   响应式断点控制 Responsive 断点
   ========================================================================== */
@media (max-width: 992px) {
    .news-grid { 
        grid-template-columns: repeat(2, 1fr); 
    }
}

@media (max-width: 900px) {
    .hero-title { 
        font-size: 38px; 
    }
    .bento-grid { 
        grid-template-columns: 1fr; 
    }
    .bento-card.span-2 { 
        grid-column: span 1; 
    }
    .tab-panel { 
        grid-template-columns: 1fr; 
    }
    .code-container { 
        grid-template-columns: 1fr; 
    }
    .footer-container { 
        grid-template-columns: 1fr 1fr; 
    }
    .nav-links { 
        display: none; 
    }
}

@media (max-width: 640px) {
    .news-grid { 
        grid-template-columns: 1fr; 
    }
}