:root {
            --primary-color: #ff6b35;
            --secondary-color: #f7931e;
            --accent-color: #2ecc71;
            --text-dark: #2c3e50;
            --text-light: #7f8c8d;
            --bg-light: #f8f9fa;
            --border-radius: 8px;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: var(--text-dark);
            background-color: #fff;
        }
        .logo {
            font-family: 'Georgia', serif;
            font-weight: bold;
            color: var(--primary-color);
            text-shadow: 1px 1px 2px rgba(0,0,0,0.1);
        }
        .nav-link {
            font-weight: 500;
            transition: color 0.3s ease;
        }
        .nav-link:hover {
            color: var(--primary-color) !important;
        }
        h1, h2, h3 {
            color: var(--text-dark);
            margin-bottom: 1rem;
        }
        h1 {
            border-bottom: 2px solid var(--primary-color);
            padding-bottom: 0.5rem;
        }
        h2 {
            border-left: 4px solid var(--secondary-color);
            padding-left: 1rem;
            margin-top: 2.5rem;
        }
        h3 {
            color: var(--secondary-color);
            margin-top: 1.5rem;
        }
        .lead {
            font-size: 1.2rem;
            color: var(--text-light);
        }
        .content-section {
            margin-bottom: 3rem;
        }
        .img-container {
            border-radius: var(--border-radius);
            overflow: hidden;
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
            margin: 2rem 0;
        }
        .img-container img {
            transition: transform 0.5s ease;
        }
        .img-container:hover img {
            transform: scale(1.03);
        }
        .highlight-box {
            background-color: var(--bg-light);
            border-left: 4px solid var(--accent-color);
            padding: 1.5rem;
            border-radius: 0 var(--border-radius) var(--border-radius) 0;
            margin: 1.5rem 0;
        }
        .key-feature {
            background: linear-gradient(135deg, #ff6b35, #f7931e);
            color: white;
            padding: 1rem;
            border-radius: var(--border-radius);
            margin: 1rem 0;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        }
        .table-of-contents {
            background-color: var(--bg-light);
            border-radius: var(--border-radius);
            padding: 1.5rem;
            margin: 2rem 0;
        }
        .table-of-contents ul {
            list-style-type: none;
            padding-left: 0;
        }
        .table-of-contents li {
            margin-bottom: 0.5rem;
        }
        .table-of-contents a {
            color: var(--text-dark);
            text-decoration: none;
            transition: color 0.3s ease;
            display: block;
            padding: 0.25rem 0;
        }
        .table-of-contents a:hover {
            color: var(--primary-color);
            padding-left: 0.5rem;
        }
        footer {
            background-color: var(--text-dark);
            color: white;
            padding: 2rem 0;
            margin-top: 3rem;
        }
        .back-to-top {
            position: fixed;
            bottom: 20px;
            right: 20px;
            background-color: 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);
            opacity: 0;
            transition: opacity 0.3s ease;
            z-index: 1000;
        }
        .back-to-top.visible {
            opacity: 1;
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 1.8rem;
            }
            h2 {
                font-size: 1.5rem;
            }
            .lead {
                font-size: 1.1rem;
            }
        }