:root {
            --primary-color: #ff6b35;
            --secondary-color: #1a5276;
            --accent-color: #f39c12;
            --text-color: #2c3e50;
            --light-bg: #f8f9fa;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            color: var(--text-color);
            line-height: 1.7;
            background-color: #ffffff;
        }
        .logo-text {
            font-family: 'Georgia', serif;
            font-weight: bold;
            color: var(--primary-color);
            font-size: 1.8rem;
            text-shadow: 1px 1px 2px rgba(0,0,0,0.1);
        }
        .nav-custom {
            background: linear-gradient(135deg, var(--secondary-color) 0%, #2c3e50 100%);
            box-shadow: 0 2px 15px rgba(0,0,0,0.1);
        }
        .nav-link {
            color: white !important;
            font-weight: 500;
            transition: all 0.3s ease;
            padding: 0.5rem 1rem !important;
            border-radius: 4px;
        }
        .nav-link:hover {
            background-color: rgba(255,255,255,0.15);
            transform: translateY(-2px);
        }
        .hero-section {
            background: linear-gradient(rgba(26, 82, 118, 0.85), rgba(44, 62, 80, 0.9)), url('https://via.placeholder.com/1600x900') center/cover no-repeat;
            color: white;
            padding: 5rem 0;
            margin-bottom: 3rem;
            border-radius: 0 0 20px 20px;
        }
        .section-title {
            color: var(--secondary-color);
            border-left: 5px solid var(--primary-color);
            padding-left: 15px;
            margin: 2.5rem 0 1.5rem;
            font-weight: 700;
        }
        .content-card {
            background: white;
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            padding: 2rem;
            margin-bottom: 2rem;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border: 1px solid #eaeaea;
        }
        .content-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }
        .highlight-text {
            background: linear-gradient(120deg, rgba(255,107,53,0.15) 0%, rgba(243,156,18,0.15) 100%);
            border-left: 4px solid var(--primary-color);
            padding: 1.5rem;
            margin: 1.5rem 0;
            border-radius: 0 8px 8px 0;
        }
        .key-term {
            font-weight: 700;
            color: var(--primary-color);
        }
        .image-caption {
            font-style: italic;
            color: #6c757d;
            text-align: center;
            margin-top: 0.5rem;
            font-size: 0.9rem;
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        footer {
            background-color: var(--secondary-color);
            color: white;
            padding: 3rem 0 1.5rem;
            margin-top: 4rem;
        }
        .footer-heading {
            color: var(--accent-color);
            font-weight: 600;
            margin-bottom: 1.2rem;
        }
        .social-links a {
            color: white;
            font-size: 1.5rem;
            margin-right: 1rem;
            transition: color 0.3s ease;
        }
        .social-links a:hover {
            color: var(--accent-color);
        }
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background: var(--primary-color);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            box-shadow: 0 2px 10px rgba(0,0,0,0.2);
            transition: all 0.3s ease;
            z-index: 1000;
        }
        .back-to-top:hover {
            background: var(--secondary-color);
            transform: translateY(-3px);
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 3rem 0;
                text-align: center;
            }
            .content-card {
                padding: 1.5rem;
            }
            .logo-text {
                font-size: 1.5rem;
            }
        }