header {

    grid-column : 1 / span 2;
    grid-row : 1 / 1;
 }
 section {
     grid-column : 1 /  1;
    grid-row : 2 / 2;
    display : grid;
    grid-template-columns: 1fr 1fr;
     grid-template-rows :auto  1fr  1fr;
 
 }
 nav ul {
 
     display : flex;
     justify-content: space-around;
 }
 
 header h2 {
 
     text-align: center;
     background-color: lightgrey;
 
 }
 nav ul li {
     flex-basis : auto;
 
     display : inline-block;
 }
 section > h2 {
 
     grid-column : 1 /  3;
     grid-row : 1 / 2;
     text-align:center;
 }
 aside {
 padding-left : 0.25em;
 
 }
 article {
 
 border : 1px solid gray;
 padding : 0.25em;
 margin : 0.25em;
 }
 article:nth-of-type(1){
 
     grid-column : 1 /  1;
     grid-row : 2 / 2;
 }
 article:nth-of-type(2){
 
     grid-column : 2 /  2;
     grid-row : 2 / 2;
 }
 article:nth-of-type(3){
 
     grid-column : 1 /  1;
     grid-row : 3 / 3;
 }
 article:nth-of-type(4){
 
     grid-column : 2 /  2;
     grid-row : 3 / 3;
 }
 
 aside {
 
     grid-column : 2 /  2;
    grid-row : 2 / 2;
 }
 footer {
 
     grid-column : 1 /  2;
     grid-row : 3 / 3;
 }
 body{
     display: grid;
     grid-template-columns: 2fr 1fr;
     grid-template-rows : auto 1fr auto;
 }