/* roulang page: index */
:root {
            --primary: #00F2FE;
            --secondary: #7928CA;
            --bg-dark: #0A0D14;
            --card-bg: #121722;
            --hover-bg: #1A2130;
            --text-main: #F8FAFC;
            --text-dim: #94A3B8;
            --border: rgba(255, 255, 255, 0.08);
        }
        * { box-sizing: border-box; margin: 0; padding: 0; }
        body { font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; background-color: var(--bg-dark); color: var(--text-main); line-height: 1.7; }
        a { text-decoration: none; color: inherit; transition: 0.3s; }
        ul { list-style: none; }
        
        /* Header */
        .header { position: sticky; top: 0; z-index: 100; background: rgba(10, 13, 20, 0.9); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border); padding: 1rem 0; }
        .nav-container { max-width: 1240px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; padding: 0 24px; }
        .logo { font-size: 1.25rem; font-weight: 800; color: var(--primary); }
        .nav-links a { margin-left: 24px; font-size: 0.95rem; color: var(--text-dim); }
        .nav-links a:hover { color: var(--primary); }
        .btn-cta { background: var(--primary); color: #000; padding: 8px 20px; border-radius: 6px; font-weight: 600; cursor: pointer; }
        
        /* Hero */
        .hero { padding: 80px 24px; text-align: center; background: radial-gradient(circle at center, #1A2130 0%, #0A0D14 100%); }
        .hero h1 { font-size: 3.5rem; font-weight: 800; margin-bottom: 20px; background: linear-gradient(to right, #fff, var(--primary)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
        .hero p { max-width: 700px; margin: 0 auto 30px; color: var(--text-dim); font-size: 1.1rem; }
        
        /* Section */
        .section { padding: 80px 24px; max-width: 1240px; margin: 0 auto; }
        .section-title { font-size: 2.5rem; text-align: center; margin-bottom: 50px; }
        
        /* Card Grid */
        .grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 24px; }
        .card { background: var(--card-bg); padding: 30px; border-radius: 12px; border: 1px solid var(--border); transition: 0.3s; }
        .card:hover { transform: translateY(-4px); border-color: var(--primary); box-shadow: 0 12px 32px rgba(0, 242, 254, 0.1); }
        
        /* Footer */
        .footer { padding: 60px 24px; border-top: 1px solid var(--border); color: var(--text-dim); text-align: center; }
        
        @media (max-width: 768px) {
            .hero h1 { font-size: 2.2rem; }
            .nav-links { display: none; }
        }