:root {
            /* Base palette */
            --bg-primary: #0a192f; /* or #1a1a2e */
            --bg-elevated: #0e2342;
            --text-primary: #e6f1ff;
            --text-muted: #a8b2d1;
            --card-blue: #112240;
            --card-purple: #4a1e6d;
            --surface: rgba(255,255,255,0.04);

            /* Accent options (user can change) */
            --accent: #64ffda; /* bright cyan */
            --accent-alt-1: #f72585; /* pink */
            --accent-alt-2: #b5179e; /* electric purple */

            /* Layout */
            --header-height: 72px;
            --radius-sm: 10px;
            --radius-lg: 25px;
            --max-w: 1200px;
            --shadow-elev: 0 10px 30px rgba(2,12,27,0.7);
            --blur: saturate(180%) blur(10px);
            --transition-fast: 180ms ease;
            --transition-med: 300ms ease;
        }

        * { box-sizing: border-box; }
        html, body { height: 100%; }
        body {
            margin: 0;
            font-family: 'Inter', 'Poppins', system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
            color: var(--text-primary);
            background: radial-gradient(1200px 600px at 80% -10%, rgba(100,255,218,0.06), transparent 40%),
                        radial-gradient(900px 500px at 10% 30%, rgba(181,23,158,0.06), transparent 40%),
                        var(--bg-primary);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        a { color: inherit; text-decoration: none; }
        img { max-width: 100%; display: block; }

        .container { width: 100%; max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }

        /* Header */
        .header {
            position: fixed; top: 0; left: 0; right: 0; height: var(--header-height);
            display: flex; align-items: center; z-index: 1000;
            transition: background var(--transition-med), box-shadow var(--transition-med), transform var(--transition-med);
            background: rgba(10, 25, 47, 0.35);
            backdrop-filter: var(--blur);
        }
        .header-inner { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; height: 100%; }
        .header.scrolled {
            background: rgba(10, 25, 47, 0.6);
            box-shadow: 0 8px 24px rgba(0,0,0,0.25);
        }
    
        .logo {
            display: inline-flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: 0.5px;
        }
        .logo span:last-child { font-size: 22px; font-weight: 800; letter-spacing: 0.6px; }
        .logo-mark {
            width: 36px; height: 36px; border-radius: 10px;
            background: linear-gradient(135deg, var(--accent), rgba(100,255,218,0.2));
            box-shadow: inset 0 0 20px rgba(100,255,218,0.25), 0 6px 18px rgba(100,255,218,0.2);
        }
        nav { justify-self: center; }
        nav ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 32px; }
        nav a { color: var(--text-muted); padding: 10px 16px; border-radius: 10px; transition: color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast); font-size: 18px; font-weight: 600; }
        nav a:hover { color: var(--text-primary); background: rgba(100,255,218,0.08); }
        nav a.active { color: var(--accent); background: rgba(100,255,218,0.12); }

        /* Sections */
        section { padding: calc(var(--header-height) + 48px) 0 96px; }
        .section-title { font-size: 28px; font-weight: 700; margin: 0 0 24px; color: var(--text-primary); }
        .section-sub { color: var(--text-muted); margin-bottom: 32px; }

        /* Hero */
        .hero { min-height: 100vh; display: grid; place-items: center; padding-top: var(--header-height); }
        .hero-inner { text-align: center; max-width: 900px; padding: 48px 0; }
        .kicker { color: var(--accent); letter-spacing: 0.12em; font-weight: 600; font-size: 14px; text-transform: uppercase; }
        .hero h1 { font-size: clamp(36px, 6vw, 64px); line-height: 1.1; margin: 12px 0 16px; }
        .hero p { font-size: clamp(16px, 2.4vw, 20px); color: var(--text-muted); margin: 0 auto 28px; max-width: 760px; }
        .cta-row { display: inline-flex; gap: 16px; flex-wrap: wrap; justify-content: center; }
        .btn { display: inline-flex; align-items: center; gap: 10px; padding: 12px 20px; border-radius: var(--radius-lg); border: 1px solid rgba(100,255,218,0.35); color: var(--accent); transition: background var(--transition-fast), transform var(--transition-fast), color var(--transition-fast); }
        .btn:hover { background: rgba(100,255,218,0.12); transform: translateY(-2px); }
        .btn-primary { background: var(--accent); color: #0a192f; border: none; }
        .btn-primary:hover { filter: brightness(1.1); }

        /* Portfolio grid */
        .grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
        .card {
            background: radial-gradient(500px 220px at -10% 0%, rgba(255,255,255,0.06), transparent 40%), var(--card-blue);
            border-radius: var(--radius-sm);
            padding: 18px; border: 1px solid rgba(255,255,255,0.06);
            box-shadow: var(--shadow-elev);
            transform: translateY(0) scale(1);
            transition: transform var(--transition-med), box-shadow var(--transition-med), border-color var(--transition-med);
            overflow: hidden;
        }
        .card:hover { transform: translateY(-6px) scale(1.02); border-color: rgba(100,255,218,0.35); box-shadow: 0 14px 34px rgba(2,12,27,0.9); }
        .thumb { aspect-ratio: 16/10; border-radius: 10px; background: linear-gradient(135deg, #233554, #0a192f); border: 1px solid rgba(255,255,255,0.06); display: grid; place-items: center; color: var(--text-muted); font-size: 14px; }
        .card h3 { margin: 14px 0 6px; font-size: 18px; }
        .card p { margin: 0; color: var(--text-muted); font-size: 14px; }

        /* About */
        .about { padding-top: 48px; }
        .about-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 36px; align-items: start; }
        .stack-icons { display: flex; flex-wrap: wrap; gap: 10px; }
        .badge { padding: 8px 12px; border-radius: 999px; border: 1px solid rgba(255,255,255,0.1); color: var(--text-primary); background: rgba(255,255,255,0.035); font-size: 13px; }
        .socials { display: flex; gap: 12px; margin-top: 18px; }

        /* Footer */
        footer { padding: 36px 0 48px; color: var(--text-muted); text-align: center; font-size: 14px; opacity: 0.9; }

        /* Responsive */
        @media (max-width: 1024px) {
            .grid { grid-template-columns: repeat(2, 1fr); }
            .about-grid { grid-template-columns: 1fr; }
        }
        @media (max-width: 640px) {
            nav ul { gap: 12px; }
            .grid { grid-template-columns: 1fr; }
            .hero-inner { padding: 32px 0; }
            .logo span:last-child { font-size: 18px; }
        }