/*.container{
    grid-template-columns: [first] 40px [line2] 50px [line3] auto [col4-start] 50px [five] 40px [end];
    grid-template-rows: [row1-start] 25% [row1-end] 100px [third-line] auto [last-line];
}*/
body{background-color: lightpink;}
.item-a {
    grid-area: header;
    justify-self: center;
    place-self: center;
 }
.item-b {
    grid-area: main;
    justify-self: center;
    place-self: center;
 }
.item-c {
    grid-area: sidebar;
    justify-self: center;
    place-self: center;
 }
.item-d {
    grid-area: footer;
    justify-self: center;
    place-self: center;
 }
  
.container {
    display: grid;
    grid-template-columns: 25% 2% 2% 25%;
    grid-template-rows: auto;
    grid-template-areas: 
      "header header header header"
      "main main . sidebar"
      "footer footer footer footer";
    align-content: start;    
    justify-content: center;   
    gap: 1.5% 1%;
    justify-items: stretch;
    align-items: stretch;
 }