body {
            margin: 0;
            font-family: Arial, sans-serif;
        }
               
        header {
            background-color: #001F3F; /* Azul Navy */
            color: #FFFFFF;
            padding: 20px;
            text-align: center;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
        }
        
        .articulo {
            flex-basis: calc(33.33% - 20px);
            margin-bottom: 20px;
            padding: 10px;
            box-sizing: border-box;
            text-align: center;
        }
        
        .articulo img {
            max-width: 100%;
            height: auto;
        }
        
        @media (max-width: 768px) {
            .articulo {
                flex-basis: calc(50% - 20px);
            }
        }
        
        @media (max-width: 480px) {
            .articulo {
                flex-basis: 100%;
            }
        }