/* roulang page: index */
:root {
            --primary: #0055FF;
            --accent: #00E5FF;
            --orange: #FF7F00;
            --dark: #121419;
            --dark-gray: #1a1d24;
            --text-main: #ffffff;
            --text-muted: #a0a0a0;
            --bg-body: #0a0b0d;
            --radius: 16px;
            --shadow: 0 10px 30px rgba(0,0,0,0.5);
            --gradient: linear-gradient(135deg, #0055FF, #00E5FF);
        }

        * { box-sizing: border-box; margin: 0; padding: 0; }
        body { font-family: 'Inter', 'PingFang SC', sans-serif; background: var(--bg-body); color: var(--text-main); line-height: 1.6; }
        
        .container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
        
        /* Typography */
        h1, h2, h3 { line-height: 1.2; font-weight: 700; }
        h1 { font-size: 3.5rem; margin-bottom: 1.5rem; background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
        h2 { font-size: 2.5rem; margin-bottom: 3rem; text-align: center; }
        
        /* Components */
        .btn { display: inline-block; padding: 12px 30px; border-radius: 50px; text-decoration: none; font-weight: 600; transition: all 0.3s ease; border: none; cursor: pointer; }
        .btn-primary { background: var(--gradient); color: #fff; }
        .btn-primary:hover { transform: translateY(-3px); box-shadow: 0 5px 15px rgba(0,85,255,0.4); }
        .btn-outline { border: 1px solid var(--accent); color: var(--accent); }
        
        .card { background: var(--dark-gray); padding: 30px; border-radius: var(--radius); border: 1px solid #2a2d35; transition: 0.3s; }
        .card:hover { border-color: var(--primary); transform: translateY(-5px); }

        /* Header */
        header { padding: 20px 0; border-bottom: 1px solid #2a2d35; position: sticky; top: 0; z-index: 100; background: rgba(18, 20, 25, 0.9); backdrop-filter: blur(10px); }
        nav { display: flex; justify-content: space-between; align-items: center; }
        .logo { font-size: 1.5rem; font-weight: 800; color: #fff; text-decoration: none; }
        .nav-links a { color: var(--text-main); text-decoration: none; margin-left: 30px; font-size: 0.95rem; }

        /* Sections */
        section { padding: 80px 0; }
        .grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }
        
        /* Specific Styles */
        .hero { text-align: center; padding: 100px 0; background-image: url('/assets/images/backpic/back-1.png'); background-size: cover; background-position: center; }
        .hero p { font-size: 1.25rem; color: var(--text-muted); max-width: 800px; margin: 0 auto 30px; }
        
        .data-badge { display: inline-block; padding: 5px 15px; background: rgba(0, 229, 255, 0.1); border: 1px solid var(--accent); color: var(--accent); border-radius: 20px; font-size: 0.8rem; margin-bottom: 10px; }
        
        /* Footer */
        footer { background: var(--dark-gray); padding: 40px 0; text-align: center; border-top: 1px solid #2a2d35; margin-top: 50px; color: var(--text-muted); font-size: 0.9rem; }