:root {
            --primary-color: #1e3a8a;
            --secondary-color: #dc2626;
            --accent-color: #f59e0b;
            --light-color: #f8fafc;
            --dark-color: #0f172a;
            --gray-color: #64748b;
        }
        body {
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
            color: #333;
            line-height: 1.6;
        }
        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
            color: var(--primary-color);
        }
        .hero-section {
            background: linear-gradient(rgba(30, 58, 138, 0.85), rgba(30, 58, 138, 0.9)), url('https://images.unsplash.com/photo-1531415074968-036ba1b575da?ixlib=rb-4.0.3&auto=format&fit=crop&w=2000&q=80') center/cover no-repeat;
            color: white;
            padding: 6rem 0;
        }
        .section-title {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 2.5rem;
            font-weight: 700;
            color: var(--primary-color);
        }
        .section-title::after {
            content: '';
            position: absolute;
            left: 0;
            bottom: 0;
            width: 60px;
            height: 4px;
            background: var(--secondary-color);
        }
        .card {
            border: none;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 6px 15px rgba(0,0,0,0.08);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .card:hover {
            transform: translateY(-10px);
            box-shadow: 0 12px 25px rgba(0,0,0,0.15);
        }
        .icon-box {
            width: 70px;
            height: 70px;
            border-radius: 50%;
            background: var(--primary-color);
            color: white;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            font-size: 1.8rem;
        }
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            padding: 0.75rem 2rem;
            font-weight: 600;
            border-radius: 8px;
        }
        .btn-primary:hover {
            background-color: var(--secondary-color);
            border-color: var(--secondary-color);
        }
        .footer {
            background-color: var(--dark-color);
            color: var(--light-color);
            padding: 3rem 0 1.5rem;
        }
        .friendlink .flink {
            display: inline-block;
            background: #e2e8f0;
            color: var(--dark-color);
            padding: 0.5rem 1.25rem;
            margin: 0.5rem;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s;
        }
        .friendlink .flink:hover {
            background: var(--primary-color);
            color: white;
            transform: scale(1.05);
        }
        .analysis-chart {
            background: #f1f5f9;
            border-radius: 12px;
            padding: 2rem;
            margin: 2rem 0;
        }
        .hover-underline {
            text-decoration: none;
            position: relative;
        }
        .hover-underline::after {
            content: '';
            position: absolute;
            left: 0;
            bottom: -3px;
            width: 0;
            height: 2px;
            background: var(--secondary-color);
            transition: width 0.3s ease;
        }
        .hover-underline:hover::after {
            width: 100%;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 4rem 0;
                text-align: center;
            }
            .section-title {
                font-size: 1.8rem;
            }
        }