body {
            font-family: Arial;
            margin: 0;
            background: #eaf6fb;
            /* fondo celeste pastel */
        }

        header {
            text-align: center;
            background: #b3e5fc;
            color: #01579b;
            padding: 15px;
        }

        nav {
            text-align: center;
            background: #81d4fa;
            padding: 10px;
        }

        nav a {
            color: #01579b;
            margin: 5px;
            text-decoration: none;
            font-weight: bold;
        }

        nav a:hover {
            text-decoration: underline;
        }

        /* GRID PRINCIPAL */
        .contenedor {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
            padding: 20px;
        }

        section {
            background: #ffffff;
            padding: 15px;
            border-radius: 12px;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
            border: 2px solid #b3e5fc;
        }

        section h2 {
            color: #0288d1;
        }

        /* Centrar sección 7 */
        #traversing {
            grid-column: 2 / 3;
        }

        button {
            margin-top: 5px;
            padding: 6px 10px;
            border: none;
            border-radius: 8px;
            background: #4fc3f7;
            color: white;
            cursor: pointer;
        }

        button:hover {
            background: #29b6f6;
        }

        small {
            display: block;
            font-size: 12px;
            color: #555;
            margin-bottom: 10px;
        }

        .caja {
            width: 100px;
            height: 100px;
            background: #81d4fa;
            margin-top: 10px;
            border-radius: 10px;
        }

        footer {
            text-align: center;
            padding: 15px;
            background: #b3e5fc;
            color: #01579b;
        }