/* roulang page: index */
:root {
            --primary: #6366F1;
            --primary-dark: #4F46E5;
            --accent: #10B981;
            --accent-orange: #F59E0B;
            --bg-deep: #0F172A;
            --bg-panel: #1E293B;
            --text-main: #F8FAFC;
            --text-body: #94A3B8;
            --text-dim: #64748B;
            --border: rgba(255, 255, 255, 0.08);
            --radius-md: 12px;
            --radius-lg: 16px;
            --shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.3);
        }

        * { box-sizing: border-box; margin: 0; padding: 0; }
        body { font-family: system-ui, -apple-system, sans-serif; background-color: var(--bg-deep); color: var(--text-body); line-height: 1.6; }
        .container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

        /* Header */
        header { border-bottom: 1px solid var(--border); background: var(--bg-deep); position: sticky; top: 0; z-index: 1000; }
        .nav-wrapper { display: flex; justify-content: space-between; align-items: center; height: 72px; }
        .logo { font-size: 20px; font-weight: 700; color: var(--text-main); text-decoration: none; }
        nav a { color: var(--text-body); text-decoration: none; margin-left: 24px; font-size: 14px; transition: color 0.2s; }
        nav a:hover { color: var(--primary); }
        .btn-primary { background: var(--primary); color: white; padding: 8px 20px; border-radius: 6px; text-decoration: none; font-weight: 500; }

        /* Hero */
        .hero { padding: 80px 0; background: radial-gradient(circle at 80% 20%, rgba(99, 102, 241, 0.15), transparent); }
        .hero-content h1 { font-size: 56px; color: var(--text-main); line-height: 1.1; margin-bottom: 24px; }
        .hero-content p { font-size: 18px; color: var(--text-body); margin-bottom: 32px; max-width: 600px; }

        /* Sections */
        section { padding: 80px 0; }
        h2 { font-size: 36px; color: var(--text-main); margin-bottom: 48px; text-align: center; }
        
        /* Cards */
        .grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
        .card { background: var(--bg-panel); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 32px; transition: transform 0.25s, box-shadow 0.25s; }
        .card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--primary); }
        .card h3 { color: var(--text-main); margin-bottom: 12px; }

        /* Footer */
        footer { border-top: 1px solid var(--border); padding: 60px 0; background: #070B14; }
        .footer-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px; }
        .footer-link { display: block; color: var(--text-body); margin-bottom: 12px; text-decoration: none; }

        @media (max-width: 768px) {
            .grid { grid-template-columns: 1fr; }
            .footer-grid { grid-template-columns: 1fr 1fr; }
            .hero-content h1 { font-size: 36px; }
        }