:root {
            --ink: #14141c;
            --ink-soft: #3a3a4a;
            --cream: #f8f6f1;
            --cream-deep: #efeae0;
            --paper: #ffffff;
            --purple: #8b5cf6;
            --purple-dark: #7c3aed;
            --purple-light: #ede9fe;
            --coral: #f43f5e;
            --amber: #d97706;
            --line: rgba(20,20,28,0.08);
            --shadow: 0 1px 3px rgba(0,0,0,0.04), 0 8px 24px rgba(0,0,0,0.06);
            --shadow-lg: 0 4px 12px rgba(0,0,0,0.06), 0 24px 48px rgba(0,0,0,0.08);
            --radius: 16px;
            --gradient-primary: linear-gradient(135deg, #8b5cf6, #7c3aed);
            --text-secondary: rgba(255,255,255,0.65);
        }
        * { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body {
            font-family: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Helvetica Neue', sans-serif;
            background: var(--cream);
            color: var(--ink);
            line-height: 1.65;
            -webkit-font-smoothing: antialiased;
            overflow-x: hidden;
        }
        .container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
        section { padding: 80px 0; }

        /* ===== 导航 ===== */
        .header {
            position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
            background: rgba(248,246,241,0.88);
            backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--line);
        }
        .nav-container {
            max-width: 1200px; margin: 0 auto; padding: 14px 24px;
            display: flex; align-items: center; justify-content: space-between;
        }
        .logo { display: flex; align-items: center; gap: 10px; font-size: 22px; font-weight: 800; color: var(--ink); }
        .logo-icon { display: flex; align-items: center; justify-content: center; }
        .logo-icon img { width: 30px; height: 30px; border-radius: 8px; display: block; }
        .nav-menu { display: flex; gap: 28px; list-style: none; }
        .nav-menu a { color: var(--ink-soft); text-decoration: none; font-size: 15px; font-weight: 500; transition: color .2s; }
        .nav-menu a:hover { color: var(--purple); }

        /* ===== Hero ===== */
        .hero { padding: 140px 0 80px; text-align: center; position: relative; overflow: hidden; }
        .hero::before {
            content: ''; position: absolute; top: -200px; left: 50%; transform: translateX(-50%);
            width: 600px; height: 600px; border-radius: 50%;
            background: radial-gradient(circle, rgba(139,92,246,0.12), transparent 70%);
            pointer-events: none;
        }
        .badge {
            display: inline-block; background: var(--purple-light); color: var(--purple-dark);
            padding: 6px 16px; border-radius: 100px; font-size: 14px; font-weight: 600; margin-bottom: 24px;
        }
        .hero h1 { font-size: 48px; font-weight: 800; line-height: 1.2; letter-spacing: -0.02em; margin-bottom: 20px; position: relative; }
        .hero-subtitle { font-size: 18px; color: var(--ink-soft); max-width: 640px; margin: 0 auto 36px; position: relative; }
        .btn-group { display: flex; gap: 14px; justify-content: center; position: relative; }
        .btn-primary {
            display: inline-block; background: var(--purple); color: #fff;
            padding: 15px 40px; border-radius: 100px; font-size: 16px; font-weight: 700;
            text-decoration: none; transition: all .25s; box-shadow: 0 6px 20px rgba(139,92,246,0.3);
        }
        .btn-primary:hover { background: var(--purple-dark); transform: translateY(-2px); box-shadow: 0 10px 28px rgba(139,92,246,0.35); }

        /* ===== 图片 ===== */
        .card-img { width: 100%; height: 180px; object-fit: cover; border-radius: 12px; margin-bottom: 16px; display: block; }
        .case-item .card-img { height: 220px; }
        .intro-img { width: 100%; max-width: 800px; border-radius: 20px; margin: 0 auto 32px; display: block; box-shadow: var(--shadow); }
        .hero-img { width: 100%; max-width: 720px; border-radius: 20px; margin: 48px auto 0; display: block; box-shadow: var(--shadow-lg); position: relative; }

        /* ===== 暗色区块 ===== */
        .bg-dark-surface { background: var(--ink); color: #fff; }

        /* ===== 标题 ===== */
        .section-title { font-size: 36px; font-weight: 800; letter-spacing: -0.02em; line-height: 1.2; margin-bottom: 16px; text-align: center; }
        .bg-dark-surface .section-title { color: #fff; }
        .section-sub { font-size: 18px; color: var(--ink-soft); text-align: center; margin-bottom: 48px; }
        .bg-dark-surface .section-sub { color: rgba(255,255,255,0.65); }

        /* ===== 功能卡片 ===== */
        .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
        .feature-card {
            background: var(--paper); border-radius: var(--radius); padding: 28px;
            box-shadow: var(--shadow); transition: transform .25s, box-shadow .25s;
        }
        .feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
        .feature-icon {
            width: 48px; height: 48px; border-radius: 12px; background: var(--purple-light);
            display: flex; align-items: center; justify-content: center; font-size: 24px; margin-bottom: 16px;
        }
        .feature-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 10px; }
        .feature-card p { font-size: 15px; color: var(--ink-soft); line-height: 1.7; }

        /* ===== 场景卡片 ===== */
        .case-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
        .case-item {
            background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1);
            border-radius: var(--radius); padding: 28px; transition: all .25s;
        }
        .case-item:hover { border-color: var(--purple); background: rgba(139,92,246,0.08); transform: translateY(-4px); }
        .case-item h3 { font-size: 20px; font-weight: 700; color: #fff; margin-bottom: 10px; }
        .case-item p { font-size: 15px; color: rgba(255,255,255,0.6); line-height: 1.7; }

        /* ===== 视频卡片 ===== */
        .video-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 24px; }
        .video-card {
            background: var(--paper); border-radius: var(--radius); overflow: hidden;
            box-shadow: var(--shadow); transition: transform .25s, box-shadow .25s;
        }
        .video-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
        .video-wrapper { position: relative; width: 100%; padding-top: 56.25%; background: #000; }
        .video-wrapper iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: none; }
        .video-info { padding: 20px; }
        .video-info h4 { font-size: 16px; font-weight: 700; margin-bottom: 8px; line-height: 1.4; }
        .video-info p { font-size: 14px; color: var(--ink-soft); }

        /* ===== 步骤卡片 ===== */
        .step-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
        .step-card {
            background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1);
            border-radius: var(--radius); padding: 28px; text-align: center;
        }
        .step-number {
            width: 48px; height: 48px; border-radius: 50%; background: var(--purple);
            display: flex; align-items: center; justify-content: center;
            font-size: 20px; font-weight: 800; color: #fff; margin: 0 auto 16px;
        }
        .step-card h3 { font-size: 18px; font-weight: 700; color: #fff; margin-bottom: 8px; }
        .step-card p { font-size: 14px; color: rgba(255,255,255,0.6); line-height: 1.6; }

        /* ===== 优势 ===== */
        .advantage-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
        .advantage-block {
            background: var(--paper); border-radius: var(--radius); padding: 28px;
            box-shadow: var(--shadow); border-top: 4px solid var(--purple);
        }
        .advantage-block h3 { font-size: 20px; font-weight: 700; margin-bottom: 10px; }
        .advantage-block p { font-size: 15px; color: var(--ink-soft); line-height: 1.7; }

        /* ===== FAQ ===== */
        .faq-item {
            background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1);
            border-radius: var(--radius); padding: 24px 28px; margin-bottom: 14px;
        }
        .faq-item h3 { font-size: 17px; font-weight: 700; color: #fff; margin-bottom: 10px; }
        .faq-item p { font-size: 15px; color: rgba(255,255,255,0.6); line-height: 1.75; }

        /* ===== CTA 按钮 ===== */
        .btn-secondary {
            display: inline-block; padding: 15px 40px; border-radius: 100px;
            font-size: 16px; font-weight: 700; text-decoration: none; transition: all .25s;
        }

        /* ===== 页脚 ===== */
        .footer { background: var(--ink); color: rgba(255,255,255,0.5); padding: 48px 0; text-align: center; }
        .footer p { font-size: 14px; margin-bottom: 8px; }

        /* ===== 响应式 ===== */
        @media (max-width: 900px) {
            .grid-3 { grid-template-columns: 1fr; }
            .case-grid, .advantage-list { grid-template-columns: 1fr; }
            .step-grid { grid-template-columns: repeat(2, 1fr); }
            .nav-menu { display: none; }
            .hero h1 { font-size: 36px; }
            .section-title { font-size: 28px; }
            section { padding: 56px 0; }
            .hero { padding-top: 120px; }
        }