:root {
            --primary-color: #4a148c;
            --secondary-color: #ff6f00;
            --accent-color: #1a237e;
            --text-color: #333333;
            --light-bg: #f5f5f5;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: var(--text-color);
            background-color: #ffffff;
        }
        .navbar-brand {
            font-weight: 800;
            font-size: 1.8rem;
            color: var(--primary-color) !important;
            text-shadow: 1px 1px 2px rgba(0,0,0,0.1);
        }
        .nav-link {
            font-weight: 500;
            transition: all 0.3s ease;
        }
        .nav-link:hover {
            color: var(--secondary-color) !important;
            transform: translateY(-2px);
        }
        .hero-section {
            background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
            color: white;
            padding: 4rem 0;
            margin-bottom: 3rem;
            border-radius: 0 0 20px 20px;
        }
        h1, h2, h3 {
            color: var(--primary-color);
            margin-bottom: 1.5rem;
            font-weight: 700;
        }
        h1 {
            font-size: 2.8rem;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
        }
        h2 {
            font-size: 2.2rem;
            border-left: 5px solid var(--secondary-color);
            padding-left: 1rem;
            margin-top: 3rem;
        }
        h3 {
            font-size: 1.8rem;
            color: var(--accent-color);
            margin-top: 2.5rem;
        }
        p {
            margin-bottom: 1.5rem;
            text-align: justify;
        }
        .content-section {
            padding: 2rem 0;
        }
        .highlight-box {
            background-color: var(--light-bg);
            border-left: 4px solid var(--secondary-color);
            padding: 1.5rem;
            margin: 2rem 0;
            border-radius: 0 8px 8px 0;
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--secondary-color);
            margin-bottom: 1rem;
        }
        .img-container {
            margin: 2rem 0;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            transition: transform 0.3s ease;
        }
        .img-container:hover {
            transform: translateY(-5px);
        }
        .key-point {
            background: linear-gradient(to right, transparent, rgba(255, 111, 0, 0.1));
            padding: 1rem;
            border-radius: 8px;
            margin: 1rem 0;
        }
        footer {
            background-color: var(--primary-color);
            color: white;
            padding: 3rem 0 2rem;
            margin-top: 4rem;
        }
        .back-to-top {
            position: fixed;
            bottom: 20px;
            right: 20px;
            background-color: var(--secondary-color);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            text-decoration: none;
            opacity: 0;
            transition: all 0.3s ease;
            z-index: 1000;
        }
        .back-to-top.show {
            opacity: 1;
        }
        .back-to-top:hover {
            background-color: var(--primary-color);
            transform: scale(1.1);
        }
        .table-of-contents {
            background-color: var(--light-bg);
            padding: 1.5rem;
            border-radius: 10px;
            margin-bottom: 2rem;
        }
        .table-of-contents ul {
            list-style-type: none;
            padding-left: 0;
        }
        .table-of-contents li {
            margin-bottom: 0.8rem;
            padding-left: 1rem;
            border-left: 3px solid transparent;
            transition: all 0.3s ease;
        }
        .table-of-contents li:hover {
            border-left-color: var(--secondary-color);
            padding-left: 1.5rem;
        }
        .table-of-contents a {
            text-decoration: none;
            color: var(--text-color);
            font-weight: 500;
        }
        .table-of-contents a:hover {
            color: var(--secondary-color);
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            h2 {
                font-size: 1.8rem;
            }
            h3 {
                font-size: 1.5rem;
            }
            .hero-section {
                padding: 2.5rem 0;
            }
        }