body {
    background-image: url("imagenes/fondo-agua.jpg");
    background-size: 100vw 100vw;
   
    background-attachment: fixed;
    margin: 0;
}
   .footer {
       background-color: #4a4141;
       width: 100%;
       
       bottom: 0;
       position: absolute;
       text-align: center;
       color: #fff;
       font-family: serif;
       padding-top: 8px;
       padding-bottom: 5px;
   }   
   h1 {
   
    color: #5d3d0c;
   font-size: 40px;
    font-family: Arial, Helvetica, sans-serif;
    
}

.contenedor{
    height: 50vh;
    margin: 5%;
    display: flex;
    justify-content: center;
    align-items: center; 
}
    
.explicacion{
    justify-content: center;
    align-items: center;
}
   h3 {
    color: #000000;
    font-family: Arial, Helvetica, sans-serif;
   }