<!DOCTYPE html><style>
    .grid {
        display: grid;
        grid-template-columns: 100px 100px;
        grid-auto-flow: row;
        height: 500px;
        width: 500px;
    }

    #b {
        grid-column: span 3;
        grid-row: span 3;
    }

    * {
        border: 1px solid black;
    }
</style><body><div class="grid"><div id="a">1</div><div id="b">2</div><div id="c">3</div><div id="d">4</div></div></body>