@supports (display:grid)
  @media (min-width: 992px)
.site-grid {
  grid-template-areas:
  ". banner banner banner banner ." 
  ". top-a  top-a  top-a  top-a  ." 
  ". top-b  top-b  top-b  top-b  ." 
  ". side-l comp   comp   side-r ." 
  ". bot-a  bot-a  bot-a  bot-a  ." 
  ". bot-b  bot-b  bot-b  bot-b  .";
}