:root {
            --primary-color: #8e44ad;
            --secondary-color: #3498db;
            --accent-color: #e74c3c;
            --text-color: #2c3e50;
            --light-bg: #f8f9fa;
            --dark-bg: #2c3e50;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: var(--text-color);
            background-color: var(--light-bg);
        }
        .logo {
            font-family: 'Arial Rounded MT Bold', 'Arial', sans-serif;
            font-size: 2.2rem;
            font-weight: 800;
            color: var(--primary-color);
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
        }
        .logo span {
            color: var(--secondary-color);
        }
        .navbar {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        .nav-link {
            color: white !important;
            font-weight: 600;
            transition: all 0.3s ease;
            padding: 8px 15px !important;
            border-radius: 5px;
        }
        .nav-link:hover {
            background-color: rgba(255,255,255,0.2);
            transform: translateY(-2px);
        }
        h1, h2, h3 {
            color: var(--dark-bg);
            margin-bottom: 1.5rem;
            font-weight: 700;
        }
        h1 {
            font-size: 2.8rem;
            border-bottom: 3px solid var(--primary-color);
            padding-bottom: 10px;
        }
        h2 {
            font-size: 2.2rem;
            color: var(--primary-color);
            margin-top: 2.5rem;
        }
        h3 {
            font-size: 1.8rem;
            color: var(--secondary-color);
            margin-top: 2rem;
        }
        p {
            margin-bottom: 1.5rem;
            text-align: justify;
        }
        .highlight {
            background-color: rgba(142, 68, 173, 0.1);
            padding: 15px;
            border-left: 4px solid var(--primary-color);
            border-radius: 0 5px 5px 0;
            margin: 20px 0;
        }
        .feature-box {
            background: white;
            border-radius: 10px;
            padding: 25px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            height: 100%;
        }
        .feature-box:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 15px;
        }
        .img-fluid {
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            transition: transform 0.3s ease;
        }
        .img-fluid:hover {
            transform: scale(1.02);
        }
        .table-of-contents {
            background: white;
            border-radius: 10px;
            padding: 25px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            margin-bottom: 30px;
        }
        .toc-list {
            list-style-type: none;
            padding-left: 0;
        }
        .toc-list li {
            margin-bottom: 10px;
            padding-left: 15px;
            border-left: 3px solid transparent;
            transition: all 0.3s ease;
        }
        .toc-list li:hover {
            border-left: 3px solid var(--primary-color);
            padding-left: 20px;
        }
        .toc-list a {
            color: var(--text-color);
            text-decoration: none;
            font-weight: 500;
        }
        .toc-list a:hover {
            color: var(--primary-color);
        }
        footer {
            background-color: var(--dark-bg);
            color: white;
            padding: 40px 0 20px;
            margin-top: 50px;
        }
        .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 4px 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);
        }
        .keyword {
            font-weight: 700;
            color: var(--primary-color);
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            h2 {
                font-size: 1.8rem;
            }
            h3 {
                font-size: 1.5rem;
            }
            .logo {
                font-size: 1.8rem;
            }
        }