:root {
            --primary-color: #ff6b35;
            --secondary-color: #f7931e;
            --accent-color: #2ecc71;
            --dark-color: #2c3e50;
            --light-color: #ecf0f1;
        }
        body {
            font-family: 'Segoe UI', system-ui, sans-serif;
            line-height: 1.7;
            color: #333;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
        }
        .hero-section {
            background: linear-gradient(rgba(44, 62, 80, 0.8), rgba(44, 62, 80, 0.9)), url('https://via.placeholder.com/1600x900') center/cover no-repeat;
            color: white;
            padding: 5rem 0;
            border-radius: 0 0 30px 30px;
            margin-bottom: 3rem;
        }
        .content-section {
            background: white;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            padding: 2.5rem;
            margin-bottom: 2rem;
            transition: transform 0.3s ease;
        }
        .content-section:hover {
            transform: translateY(-5px);
        }
        h1, h2, h3 {
            color: var(--dark-color);
            margin-bottom: 1.5rem;
        }
        h1 {
            font-size: 2.8rem;
            font-weight: 800;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
        }
        h2 {
            font-size: 2.2rem;
            border-left: 5px solid var(--primary-color);
            padding-left: 1rem;
            margin-top: 2.5rem;
        }
        h3 {
            font-size: 1.6rem;
            color: var(--secondary-color);
            margin-top: 2rem;
        }
        .highlight {
            background: linear-gradient(120deg, #ff6b3515 0%, #f7931e15 100%);
            border-left: 4px solid var(--primary-color);
            padding: 1.5rem;
            border-radius: 0 10px 10px 0;
            margin: 1.5rem 0;
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .img-fluid {
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            transition: transform 0.3s ease;
            margin: 1.5rem 0;
        }
        .img-fluid:hover {
            transform: scale(1.02);
        }
        .nav-pills .nav-link {
            color: var(--dark-color);
            font-weight: 500;
            border-radius: 50px;
            margin: 0.2rem;
            transition: all 0.3s ease;
        }
        .nav-pills .nav-link:hover, .nav-pills .nav-link.active {
            background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
            color: white;
        }
        footer {
            background: var(--dark-color);
            color: white;
            padding: 3rem 0;
            margin-top: 4rem;
        }
        .keyword-highlight {
            font-weight: 700;
            color: var(--primary-color);
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            h2 {
                font-size: 1.8rem;
            }
            .hero-section {
                padding: 3rem 0;
            }
            .content-section {
                padding: 1.5rem;
            }
        }
        .table-of-contents {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border-radius: 15px;
            padding: 2rem;
            margin-bottom: 2rem;
        }
        .table-of-contents h3 {
            color: white;
            border-bottom: 2px solid rgba(255,255,255,0.3);
            padding-bottom: 0.5rem;
        }
        .table-of-contents ul {
            list-style-type: none;
            padding-left: 0;
        }
        .table-of-contents li {
            margin-bottom: 0.8rem;
            padding-left: 1.5rem;
            position: relative;
        }
        .table-of-contents li:before {
            content: "▸";
            position: absolute;
            left: 0;
            color: var(--accent-color);
        }
        .table-of-contents a {
            color: white;
            text-decoration: none;
            transition: all 0.3s ease;
        }
        .table-of-contents a:hover {
            color: var(--accent-color);
            padding-left: 0.5rem;
        }