/* roulang page: index */
:root {
            --primary-dark: #0B0F19;
            --accent-green: #10B981;
            --accent-cyan: #06B6D4;
            --text-main: #1E293B;
            --text-light: #64748B;
            --bg-white: #F8FAFC;
            --border-color: #E2E8F0;
            --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
            --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
        }

        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { font-family: system-ui, -apple-system, "PingFang SC", sans-serif; line-height: 1.7; color: var(--text-main); background-color: #FFFFFF; }
        
        .container { max-width: 1280px; margin: 0 auto; padding: 0 2rem; }
        
        /* Header */
        header { background: rgba(255, 255, 255, 0.9); backdrop-filter: blur(10px); position: sticky; top: 0; z-index: 1000; border-bottom: 1px solid var(--border-color); padding: 1rem 0; }
        nav { display: flex; justify-content: space-between; align-items: center; }
        .logo { font-weight: 800; font-size: 1.25rem; color: var(--primary-dark); text-decoration: none; }
        .nav-links a { text-decoration: none; color: var(--text-main); font-weight: 500; margin-left: 2rem; transition: color 0.3s; }
        .nav-links a:hover { color: var(--accent-green); }
        .btn-primary { background: var(--primary-dark); color: white; padding: 0.6rem 1.5rem; border-radius: 8px; text-decoration: none; font-weight: 600; display: inline-block; }

        /* Hero */
        .hero { background: url('/assets/images/5d7bdc3933caef31.webp') center/cover no-repeat; padding: 120px 0; color: white; text-align: center; position: relative; }
        .hero::before { content: ''; position: absolute; inset: 0; background: rgba(11, 15, 25, 0.7); }
        .hero-content { position: relative; z-index: 1; }
        .hero h1 { font-size: 3.5rem; margin-bottom: 1.5rem; }
        .hero p { font-size: 1.25rem; max-width: 800px; margin: 0 auto 2rem; opacity: 0.9; }

        /* Sections */
        section { padding: 80px 0; }
        .bg-gray { background-color: var(--bg-white); }
        h2 { font-size: 2.5rem; margin-bottom: 3rem; text-align: center; }
        .grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 2rem; }
        .card { background: white; padding: 2rem; border-radius: 12px; border: 1px solid var(--border-color); transition: transform 0.3s, box-shadow 0.3s; }
        .card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }

        /* Stats */
        .stats-bar { background: var(--primary-dark); color: white; padding: 40px 0; }
        .stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); text-align: center; }
        .stat-item h3 { font-size: 2.5rem; color: var(--accent-green); }

        /* Footer */
        footer { background: var(--primary-dark); color: #94A3B8; padding: 60px 0 20px; }
        .footer-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 2rem; margin-bottom: 40px; }
        .footer-bottom { border-top: 1px solid #334155; padding-top: 20px; text-align: center; font-size: 0.9rem; }

        @media (max-width: 768px) {
            .hero h1 { font-size: 2rem; }
            .nav-links { display: none; }
            .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 2rem; }
        }