<!DOCTYPE html><style>
.grid {
display: grid;
grid-template-rows: 100px 100px;
grid-template-columns: 100px 100px;
grid-auto-flow: column;
}
#b {
grid-column: span 2;
grid-row: span 2;
}
* {
outline: 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>