footer {
            text-align: center;
            margin-top: 50px;
            color: #777;
            font-size: 0.9em;
        }
        * {
            box-sizing: border-box;
        }

        body {
            font-family: Arial, sans-serif;
            /*margin: 20px auto;
            max-width: 900px;*/
            line-height: 1.6;
            color: #333;
            background: #f7f7f7;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 0 10px rgba(0,0,0,0.1);
        }
        li {
            margin-bottom: 10px;
        }

        .menu-principal, .menu-principal ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .menu-principal {
            background-color: #333;
            display: flex;
            flex-wrap: wrap;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }

        .menu-principal > li {
            position: relative;
            border-right: 1px solid #444;
        }

        .menu-principal > li:last-child {
            border-right: none;
        }

        .menu-principal > li > strong, 
        .menu-principal > li > a {
            display: block;
            padding: 15px 20px;
            color: white;
            text-decoration: none;
            cursor: pointer;
            transition: background-color 0.3s ease;
            white-space: nowrap;
        }

        .menu-principal > li:hover > strong,
        .menu-principal > li:hover > a {
            background-color: #555;
        }

        /* Submenu styling */
        .menu-principal ul {
            position: absolute;
            top: 100%;
            left: 0;
            background-color: #444;
            min-width: 200px;
            box-shadow: 0 4px 8px rgba(0,0,0,0.2);
            opacity: 0;
            visibility: hidden;
            transform: translateY(-10px);
            transition: all 0.3s ease;
            z-index: 1000;
        }

        .menu-principal > li:hover > ul {
            opacity: 1;
            visibility: visible;
            transform: translateY(0);
        }

        .menu-principal ul li {
            border-bottom: 1px solid #555;
        }

        .menu-principal ul li:last-child {
            border-bottom: none;
        }

        .menu-principal ul li a {
            display: block;
            padding: 12px 20px;
            color: white;
            text-decoration: none;
            transition: background-color 0.3s ease;
        }

        .menu-principal ul li a:hover {
            background-color: #666;
            padding-left: 25px;
        }

        /* Indicador de submenu */
        .menu-principal > li > strong::after {
            content: " ▼";
            font-size: 0.8em;
            margin-left: 5px;
            transition: transform 0.3s ease;
        }

        .menu-principal > li:hover > strong::after {
            transform: rotate(180deg);
        }

        /* Responsividade básica */
        @media (max-width: 768px) {
            .menu-principal {
                flex-direction: column;
            }
            
            .menu-principal > li {
                border-right: none;
                border-bottom: 1px solid #444;
            }
            
            .menu-principal ul {
                position: static;
                box-shadow: none;
                opacity: 1;
                visibility: visible;
                transform: none;
                display: none;
            }
            
            .menu-principal > li:hover > ul {
                display: block;
            }
        }

        /* Conteúdo da página para demonstração */
        .conteudo {
            padding: 40px 20px;
            max-width: 1200px;
            margin: 0 auto;
        }

        .card {
            background: white;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            margin-bottom: 20px;
        }
        nav {
            margin-bottom: 30px;
            background: #34495e;
            padding: 10px 15px;
            border-radius: 5px;
        }