html{
    font-size: 62.5%;
    box-sizing: border-box;/*de Paul Irish*/    
}

/*de paul irish*/
*, *:before, *:after {
    box-sizing: inherit;
}
body{
    font-family: Arial, Helvetica, sans-serif;
    font-size: 16px;
    background-color:rgb(229, 243, 229);    
}
.contenedor{
    max-width: 120rem;
    margin: auto;
}
h1{
    color: darkred;
    text-align: center;
}
.navegacion-fondo{    
    background-color: rgb(47, 77, 77);
}
.navegacion{
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;            
}
.navegacion a{
    color:cornsilk;
    text-decoration: none;
    font-size: medium;
    font-weight: bold;
    font-family:Arial, Helvetica, sans-serif;
    padding: 1rem;      
}

@media(min-width:768px){
    .navegacion{
        display: flex;
        flex-direction: row;
        justify-content: center;            
    }
    .navegacion a{
        padding: 2rem;
    }
}

.navegacion a:hover{
    background-color: rgb(67, 122, 67);
    color:rgba(250, 234, 12, 0.959);   
}
.marco{
    display: grid;
    grid-template-columns: 100%;   
}
.marco-diapositivas{
    padding: 0.3rem 1rem;    
}
.marco-diapositivas img{
    max-height: 100%;
    max-width: 100%;
    border: solid #000 1px;
}

@media(min-width:768px){
    .marco{
        display: grid;
        grid-template-columns: 33.3% 33.3% 33.3%;   
    }
    .marco-diapositivas{
        padding: 0.5rem;    
    }
    .marco-diapositivas img{
        max-height: 100%;
        max-width: 100%;
        border: solid #000 1px;
    }
}
.pie{
    background-color:rgb(47, 77, 77);
    height: 13rem;     
}
@media(min-width:768px){
    .pie{
        background-color:rgb(47, 77, 77);
        height: 10rem;     
    }
}
.pie p{
    color: #fff;
    font-size: 1.5rem;
    font-weight: bold;
    text-align: center;
    padding-top: 2rem;
    padding-bottom: 0rem;
}