.estiloX {
    width: 600px;
    height: 300px;
    overflow: auto;
    background-image: url("imagen.jpg");
    color: white;
}

.contenedor {
    width: 80%;
    height: 500px;
    background-color: rgb(17, 56, 75);
    padding: 10px;
    box-sizing: border-box;
}