:root {
            --primary-color: #ff6b6b;
            --secondary-color: #4ecdc4;
            --accent-color: #ffd166;
            --dark-color: #2d3047;
            --light-color: #f7fff7;
        }
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.7;
            color: #333;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
        }
        .logo-text {
            font-family: 'Arial Black', Gadget, sans-serif;
            font-size: 2.2rem;
            background: linear-gradient(45deg, #ff6b6b, #4ecdc4, #ffd166);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
            font-weight: 900;
            letter-spacing: 1px;
        }
        .nav-custom {
            background-color: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        .hero-section {
            background: linear-gradient(rgba(45, 48, 71, 0.8), rgba(45, 48, 71, 0.9)), url('https://via.placeholder.com/1200x600');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 100px 0;
            text-align: center;
        }
        .section-padding {
            padding: 80px 0;
        }
        .content-card {
            background: white;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            padding: 30px;
            margin-bottom: 30px;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .content-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 35px rgba(0,0,0,0.15);
        }
        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: 15px;
            margin-top: 2rem;
        }
        h3 {
            font-size: 1.8rem;
            color: var(--secondary-color);
            margin-top: 1.5rem;
        }
        .highlight {
            background-color: rgba(255, 214, 102, 0.3);
            padding: 2px 5px;
            border-radius: 3px;
            font-weight: 600;
        }
        .feature-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .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: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border-radius: 15px;
            padding: 25px;
            margin-bottom: 40px;
        }
        .table-of-contents h3 {
            color: white;
            border-left: none;
            padding-left: 0;
        }
        .table-of-contents a {
            color: white;
            text-decoration: none;
            display: block;
            padding: 8px 0;
            border-bottom: 1px solid rgba(255,255,255,0.2);
            transition: padding-left 0.3s ease;
        }
        .table-of-contents a:hover {
            padding-left: 10px;
            color: var(--accent-color);
        }
        .table-of-contents a:last-child {
            border-bottom: none;
        }
        footer {
            background-color: var(--dark-color);
            color: white;
            padding: 40px 0 20px;
        }
        .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);
        }
        @media (max-width: 768px) {
            h1 {
                font-size: 2.2rem;
            }
            h2 {
                font-size: 1.8rem;
            }
            .logo-text {
                font-size: 1.8rem;
            }
            .hero-section {
                padding: 60px 0;
            }
            .section-padding {
                padding: 50px 0;
            }
        }