@media (min-width: 700px) {
    .headline {
        grid-area: desert;
    }
    .t1 {
        column-width: 33vw;
        column-gap: 1em;
    }
    main {
        grid-template-areas:
            "header   header   "
            "desert   nav      "
            "desert   bbb      "
            "section1 section1 "
            "t1       t1       "
            "footer   footer   "
            ;
        }
    }
    
    @media (min-width: 700px) and (orientation: landscape) {
        main {
            grid-template-areas:
            "header   header   "
            "desert   nav      "
            "desert   bbb      "
            "section1 section1 "
            "t1       t1       "
            "footer   footer   "
            ;
    }
}

    @media (min-width: 900px) {
    main {
        grid-template-areas:
            "header   header   header   nav      "
            "desert   desert   desert   bbb      "
            "t1       section1 section1 section1 "
            "t2       section1 section1 section1 "
            "footer   footer   footer   footer   "
            ;
    }
}