img {
    width: 300px;
    height: auto;
    display: block;
    margin: 20px auto;
}
#controls {
    text-align: center;
    margin-top: 20px;
}
button {
    margin: 5px;
    border-radius: 500px;
}
h1{
    font-family: Arial, Helvetica, sans-serif;
    color: white;
    border: 10px;
    border-color: black;
}
body{
    background-image: url(fondo.jpg);
    background-size: cover; 
    background-color: rgb(66, 144, 207) ;
}
body.principal{
    background-image: url(fondoI.jpg);
    background-size: cover; 
    background-color: rgb(66, 144, 207) ;
}
button.principal{

    width: 200px; /* Tamaño del botón */
    height: 200px;
    border: none;
    background-color: transparent;
    cursor: pointer;
    display: inline-block;
    margin: 10px;
}
img.pri {
    width: 300px;
    height: auto;
    display: block;
    margin: 20px auto;
    border-radius: 500px;
}