body    {
    display: grid;
    grid-template-colums: auto 100px;
}
 
header, nav, section, footer
    {
     border: 2px solid red;
}
 
 
header   
    {
    grid-colum-start: 1;
    grid-colum-end: 3;
    grid-row-start: 1;
    grid-row-end: 2;
}
 
 
nav   
    {
    grid-colum: 2 / 3;
    grid-row: 2 / 3;
}
 
 
 
section   
    {
    grid-colum: 1 / 2;
    grid-row: 2 / 3;
}
 
 
footer     
    {
    grid-colum: 1 / 3;
    grid-row: 3 / span 1;
}