/* roulang page: index */
:root {
            --primary-color: #00C896;
            --primary-hover: #00a87d;
            --text-dark: #2D3436;
            --text-light: #636e72;
            --bg-light: #F8F9FA;
            --white: #FFFFFF;
            --radius: 16px;
            --shadow: 0 10px 30px rgba(0,0,0,0.08);
        }
        * { box-sizing: border-box; margin: 0; padding: 0; }
        body { font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif; color: var(--text-dark); line-height: 1.8; background-color: var(--white); }
        .container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
        h1, h2, h3 { color: var(--text-dark); line-height: 1.3; }
        a { text-decoration: none; color: inherit; }
        
        /* Navigation */
        header { padding: 20px 0; background: var(--white); position: sticky; top: 0; z-index: 1000; box-shadow: 0 2px 10px rgba(0,0,0,0.05); }
        .nav-inner { display: flex; justify-content: space-between; align-items: center; }
        .logo { font-size: 24px; font-weight: 800; color: var(--primary-color); }
        .nav-menu { display: flex; gap: 30px; font-weight: 500; }
        .nav-menu a:hover { color: var(--primary-color); }

        /* Hero */
        .hero { padding: 100px 0; background: linear-gradient(135deg, #f0fdf9 0%, #ffffff 100%); text-align: center; }
        .hero h1 { font-size: 52px; margin-bottom: 20px; }
        .hero p { font-size: 20px; color: var(--text-light); max-width: 700px; margin: 0 auto 40px; }
        .btn { display: inline-block; padding: 15px 35px; background: var(--primary-color); color: white; border-radius: 30px; font-weight: 600; transition: transform 0.3s, background 0.3s; }
        .btn:hover { background: var(--primary-hover); transform: translateY(-3px); }

        /* Sections */
        section { padding: 80px 0; }
        .section-title { text-align: center; margin-bottom: 60px; }
        .section-title h2 { font-size: 36px; margin-bottom: 15px; }

        /* Grid */
        .grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 25px; }
        .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
        .grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 40px; align-items: center; }

        /* Cards */
        .card { padding: 30px; border-radius: var(--radius); border: 1px solid #eee; background: var(--white); transition: box-shadow 0.3s; }
        .card:hover { box-shadow: var(--shadow); }
        .card h3 { margin-bottom: 15px; }
        .card p { font-size: 14px; color: var(--text-light); }

        /* Stats */
        .stat-box { text-align: center; padding: 40px; background: var(--bg-light); border-radius: var(--radius); }
        .stat-num { font-size: 40px; font-weight: 800; color: var(--primary-color); margin-bottom: 10px; }

        /* Footer */
        footer { background: #2D3436; color: #b2bec3; padding: 60px 0; font-size: 14px; }
        .footer-bottom { border-top: 1px solid #454d55; margin-top: 40px; padding-top: 20px; text-align: center; }

        /* Responsive */
        @media (max-width: 768px) {
            .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }
            .hero h1 { font-size: 36px; }
        }