/* roulang page: index */
:root {
            --bg-color: #1A1A1A;
            --text-color: #F5F5F5;
            --accent-color: #FF6B00;
            --border-color: #333333;
            --card-bg: #222222;
            --muted-text: #A0A0A0;
            --container-width: 1140px;
            --transition: all 0.3s ease;
        }

        * { box-sizing: border-box; margin: 0; padding: 0; }
        body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; background-color: var(--bg-color); color: var(--text-color); line-height: 1.6; }
        
        .container { max-width: var(--container-width); margin: 0 auto; padding: 0 20px; }
        a { text-decoration: none; color: inherit; transition: var(--transition); }
        
        /* Header */
        header { border-bottom: 1px solid var(--border-color); padding: 15px 0; background: rgba(26, 26, 26, 0.95); position: sticky; top: 0; z-index: 1000; }
        .nav-content { display: flex; justify-content: space-between; align-items: center; }
        .logo { font-size: 24px; font-weight: bold; color: var(--text-color); }
        .logo span { color: var(--accent-color); }
        .nav-links { display: flex; gap: 30px; }
        .nav-links a:hover { color: var(--accent-color); }

        /* Hero Whitepaper */
        .hero { padding: 80px 0; background: linear-gradient(rgba(26,26,26,0.8), rgba(26,26,26,0.8)), url('/assets/images/backpic/back-1.png') no-repeat center/cover; }
        .hero-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
        .hero-title { font-size: 48px; line-height: 1.2; margin-bottom: 20px; }
        .hero-desc { margin-bottom: 30px; color: var(--muted-text); }
        .hero-form { background: var(--card-bg); padding: 30px; border: 1px solid var(--border-color); }
        input, button { width: 100%; padding: 12px; margin-bottom: 10px; border: 1px solid var(--border-color); background: #111; color: #fff; }
        .btn-primary { background: var(--accent-color); color: #fff; border: none; cursor: pointer; font-weight: bold; }

        /* Section Layouts */
        section { padding: 60px 0; border-bottom: 1px solid var(--border-color); }
        .section-title { font-size: 32px; margin-bottom: 40px; text-align: center; }
        
        .news-grid { display: grid; grid-template-columns: 2fr 1fr; gap: 40px; }
        .grid-card { border: 1px solid var(--border-color); padding: 20px; background: var(--card-bg); transition: var(--transition); }
        .grid-card:hover { border-color: var(--accent-color); }
        
        .feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
        
        /* Stats & Data */
        .stats-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; text-align: center; }
        .stat-val { font-size: 36px; font-weight: bold; color: var(--accent-color); }

        /* Footer */
        footer { padding: 40px 0; background: #000; text-align: center; color: var(--muted-text); font-size: 14px; }
        
        /* Mobile */
        @media (max-width: 768px) {
            .hero-inner, .news-grid, .feature-grid, .stats-row { grid-template-columns: 1fr; }
        }