.contenedor {
    display: grid;
    width: 100vw;
    height: 100%;
    grid-template-rows: 50px repeat(3, 100vh) 80px;
    grid-template-columns: repeat(4, 1fr);
    
    grid-template-areas: 
    "nav       nav       nav       nav"
    "imagen    imagen    imagen    imagen"
    "articulo  articulo  articulo  articulo"
    "presen    presen    presen    presen"
    "footer    footer    footer    footer";
}

.caja:nth-child(1) {
    grid-area: nav;
}

.caja:nth-child(2) {
    grid-area: imagen;
}

.caja:nth-child(3) {
    grid-area: articulo;
}

.caja:nth-child(4) {
    grid-area: presen;
}

.caja:nth-child(5) {
    grid-area: footer;
}