/* --- 全局基础样式 --- */
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body {
            font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
            background-color: #050505; /* 纯黑背景 */
            color: #e0e0e0;
            line-height: 1.6;
        }
        a { text-decoration: none; color: inherit; transition: all 0.3s ease; }
        .container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

        /* --- 导航栏 --- */
        header {
            padding: 25px 0;
            border-bottom: 1px solid #1a1a1a;
            position: sticky; top: 0; background: rgba(5,5,5,0.9); backdrop-filter: blur(8px); z-index: 100;
        }
        .nav-content { display: flex; justify-content: space-between; align-items: center; }
        .logo { font-size: 22px; font-weight: 800; letter-spacing: -1px; color: #fff; }
        .logo span { color: #666; font-weight: 400; margin-left: 5px; font-size: 14px;}
        .btn-download {
            background: #fff; color: #000; padding: 10px 24px;
            border-radius: 4px; font-weight: bold; font-size: 14px;
        }
        .btn-download:hover { background: #ccc; transform: translateY(-1px); }

        /* --- Hero 区域 (极简文字排版) --- */
        .hero { padding: 100px 0 80px; text-align: center; border-bottom: 1px solid #1a1a1a; }
        .tag { 
            display: inline-block; border: 1px solid #333; padding: 6px 16px; 
            border-radius: 50px; font-size: 12px; color: #aaa; margin-bottom: 30px; letter-spacing: 1px;
        }
        .hero h1 { font-size: 52px; font-weight: 800; color: #fff; line-height: 1.2; margin-bottom: 25px; letter-spacing: -2px; }
        .hero p { font-size: 18px; color: #777; max-width: 650px; margin: 0 auto 40px; }
        
        /* --- 核心数据指标 (大字号展示) --- */
        .metrics {
            display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px;
            padding: 60px 0; border-bottom: 1px solid #1a1a1a;
        }
        .metric-item { text-align: center; }
        .metric-value { font-size: 48px; font-weight: 800; color: #fff; margin-bottom: 10px; letter-spacing: -1px;}
        .metric-label { font-size: 14px; color: #666; text-transform: uppercase; letter-spacing: 1px; }

        /* --- 费率对比区 (凸显低费用) --- */
        .fee-section { padding: 80px 0; border-bottom: 1px solid #1a1a1a; }
        .section-header { margin-bottom: 50px; }
        .section-header h2 { font-size: 36px; color: #fff; margin-bottom: 15px; }
        .section-header p { color: #777; font-size: 16px; }

        .comparison-table { width: 100%; border-collapse: collapse; margin-top: 30px; }
        .comparison-table th, .comparison-table td { padding: 20px; text-align: left; border-bottom: 1px solid #222; font-size: 15px; }
        .comparison-table th { color: #666; font-weight: 500; text-transform: uppercase; font-size: 12px; letter-spacing: 1px;}
        .comparison-table tr:hover td { background: #111; }
        .highlight-row td { color: #fff; font-weight: bold; background: #161616 !important; }
        .free-tag { background: #fff; color: #000; padding: 2px 8px; border-radius: 4px; font-size: 12px; font-weight: bold; margin-left: 8px;}

        /* --- 安全架构 (网格布局) --- */
        .security-section { padding: 80px 0; border-bottom: 1px solid #1a1a1a; }
        .sec-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
        .sec-card {
            background: #111; border: 1px solid #222; padding: 40px 30px; border-radius: 8px;
            display: flex; flex-direction: column; justify-content: center; min-height: 220px;
        }
        .sec-icon { font-size: 32px; margin-bottom: 20px; display: block; }
        .sec-card h3 { font-size: 20px; color: #fff; margin-bottom: 15px; }
        .sec-card p { font-size: 14px; color: #888; line-height: 1.6; }

        /* --- 底部 CTA --- */
        .bottom-cta { padding: 100px 0; text-align: center; }
        .bottom-cta h2 { font-size: 40px; color: #fff; margin-bottom: 30px; }

        footer { padding: 40px 0; border-top: 1px solid #1a1a1a; text-align: center; color: #444; font-size: 13px; }

        /* --- 响应式适配 --- */
        @media (max-width: 768px) {
            .hero h1 { font-size: 36px; letter-spacing: -1px; }
            .metrics { grid-template-columns: 1fr; gap: 40px; }
            .metric-value { font-size: 40px; }
            .comparison-table th:nth-child(3), .comparison-table td:nth-child(3) { display: none; } /* 手机端隐藏普通交易所列以节省空间 */
            .bottom-cta h2 { font-size: 28px; }
        }