:root {
            --primary-color: #48A1D9;
            --secondary-color: #2a75a1;
            --dark-bg: #161616;
            --card-bg: #252525;
            --text-light: #f2f2f2;
            --text-muted: #BABBBF;
            --accent-color: #7AD3A6;
            --danger-color: #F5726F;
        }
        
        body {
            font-family: 'Poppins', sans-serif;
            background-color: var(--dark-bg);
            color: var(--text-light);
            margin: 0;
            padding: 0;
            line-height: 1.6;
        }
        
        header {
            background: linear-gradient(135deg, #1a1a1a 0%, #2a2a2a 100%);
            padding: 20px 0;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
            border-bottom: 3px solid var(--primary-color);
        }
        
        nav ul {
            display: flex;
            align-items: center;
            justify-content: center;
            list-style: none;
            padding: 0;
            margin: 0;
        }
        
        nav ul li img {
            width: 120px;
            margin-right: 30px;
        }
        
        nav ul li h1 {
            color: var(--primary-color);
            font-size: 2.2rem;
            font-weight: 600;
            margin: 0;
            text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
        }
        
        .materia-container {
            max-width: 1200px;
            margin: 40px auto;
            padding: 0 20px;
        }
        
        .secao {
            background-color: var(--card-bg);
            border-radius: 12px;
            padding: 25px;
            margin-bottom: 30px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
            transition: transform 0.3s ease;
            border-left: 5px solid var(--primary-color);
        }
        
        .secao:hover {
            transform: translateY(-5px);
        }
        
        .secao-titulo {
            color: var(--primary-color);
            font-size: 1.5rem;
            margin-bottom: 20px;
            display: flex;
            align-items: center;
            cursor: pointer;
            padding: 10px;
            border-radius: 6px;
            transition: all 0.3s ease;
        }
        
        .secao-titulo:hover {
            background-color: rgba(72, 161, 217, 0.1);
        }
        
        .secao-titulo::before {
            content: "▶";
            margin-right: 15px;
            font-size: 0.8rem;
            transition: transform 0.3s ease;
        }
        
        .secao-titulo.ativo::before {
            transform: rotate(90deg);
        }
        
        .secao-conteudo {
            display: none;
            padding: 15px;
            background: rgba(30, 30, 30, 0.7);
            border-radius: 8px;
            margin-top: 15px;
        }
        
        .secao-conteudo.ativo {
            display: block;
            animation: fadeIn 0.5s ease;
        }
        
        .arquivo-lista {
            list-style: none;
            padding: 0;
            margin: 0;
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 15px;
        }
        
        .arquivo-item {
            background: linear-gradient(145deg, #2e2e2e 0%, #1f1f1f 100%);
            border-radius: 8px;
            padding: 15px;
            transition: all 0.3s ease;
            border-left: 3px solid var(--accent-color);
        }
        
        .arquivo-item:hover {
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
        }
        
        .arquivo-item a {
            color: var(--text-light);
            text-decoration: none;
            display: block;
            padding: 10px;
        }
        
        .arquivo-item a:hover {
            color: var(--accent-color);
        }
        
        .professor-card {
            background: linear-gradient(145deg, #2e2e2e 0%, #1f1f1f 100%);
            border-radius: 8px;
            padding: 20px;
            margin-bottom: 15px;
            border-left: 3px solid var(--primary-color);
        }
        
        .professor-card h3 {
            color: var(--accent-color);
            margin-top: 0;
        }
        
        .professor-card p {
            margin: 8px 0;
        }

        .voltar-container {
            text-align: center;
            margin-top: 40px;
            padding-bottom: 30px;
        }
        
        .voltar-btn {
            display: inline-block;
            background-color: var(--primary-color);
            color: white;
            padding: 12px 25px;
            border-radius: 6px;
            text-decoration: none;
            font-weight: 500;
            transition: all 0.3s ease;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            border: none;
            cursor: pointer;
        }
        
        .voltar-btn:hover {
            background-color: var(--secondary-color);
            transform: translateY(-2px);
            box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
        }
        
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(-10px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        @media (max-width: 768px) {
            nav ul {
                flex-direction: column;
                text-align: center;
            }
            
            nav ul li img {
                margin-right: 0;
                margin-bottom: 15px;
            }
            
            .arquivo-lista {
                grid-template-columns: 1fr;
            }
        }