@media only screen and (min-width: 1660px) {
  body {
    width: 1620px;
    display: grid;
    grid-template-columns: 800px 800px;
    grid-template-rows: auto;
    column-gap: 20px;
    grid-template-areas:
      "h h"
      "i i"
      "l r"
      "f f";
  }
  
  header            { grid-area: h; }
  main#intro        { grid-area: i; }
  section#left-col  { grid-area: l; }
  section#right-col { grid-area: r; }
  footer            { grid-area: f; }
}