:root {
            --bg: #ffffff;
            --secondary-bg: #f5f5f7;
            --text: #1d1d1f;
            --muted: #86868b;
            --accent: #0066cc;
            --border: rgba(0,0,0,0.1);
        }

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

        body {
            font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", sans-serif;
            background-color: var(--bg);
            color: var(--text);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
        }

        /* Navigation */
        nav {
            position: sticky;
            top: 0;
            background: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(20px);
            z-index: 100;
            padding: 15px 8%;
            border-bottom: 1px solid var(--border);
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .nav-logo { font-weight: 700; text-decoration: none; color: var(--text); font-size: 14px; letter-spacing: 1px; }
        .back-link { text-decoration: none; color: var(--accent); font-size: 14px; font-weight: 500; }

        /* Article Layout */
        article {
            max-width: 800px;
            margin: 0 auto;
            padding: 80px 20px;
        }

        .eyebrow {
            font-size: 12px;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.12em;
            color: var(--muted);
            margin-bottom: 15px;
            display: block;
        }

        h1 {
            font-size: 48px;
            font-weight: 700;
            letter-spacing: -0.04em;
            line-height: 1.1;
            margin-bottom: 30px;
        }

        .lead {
            font-size: 24px;
            font-weight: 500;
            color: var(--muted);
            margin-bottom: 50px;
            line-height: 1.4;
        }

        /* Technical Highlight Box */
        .tech-box {
            background: var(--secondary-bg);
            border-radius: 24px;
            padding: 40px;
            margin: 40px 0;
        }

        .tech-box h3 { margin-bottom: 20px; font-size: 20px; }
        .tech-box ul { list-style: none; }
        .tech-box li {
            position: relative;
            padding-left: 25px;
            margin-bottom: 15px;
            color: #424245;
        }

        .tech-box li::before {
            content: "✓";
            position: absolute;
            left: 0;
            color: var(--accent);
            font-weight: 900;
        }

        .content-body p { margin-bottom: 25px; font-size: 19px; color: #333; }

        /* Responsive */
        @media (max-width: 768px) {
            h1 { font-size: 34px; }
            .lead { font-size: 20px; }
            article { padding: 40px 20px; }
        }