.b {
        grid-column-start: content-end;
        grid-row-start: main-start;
        grid-row-end: content-end;
    }

    .c {
        grid-column-start: content-start;
        grid-row-start: main-start;
    }

    .d {
        grid-column-start: content-start;
        grid-column-end: main-end;
        grid-row-start: content-end;
    }
</style><div class="grid-container"><div class="grid-item a">1</div><div class="grid-item b">2</div><div class="grid-item c">3</div><div class="grid-item d">4</div></