This CSS grid creates 7 rows only, as you can see by using "Inspect tool" of the browser. Why?
.grid {
display: grid;
grid-gap: 1em;
height: 100%;
}
.grid8x8 {
grid-template-rows: repeat(8, 1fr);
grid-template-columns: repeat(8, 1fr);
}
.element {
background-color: yellow;
}
<div class="grid grid8x8">
<div class="element" style="grid-row: 2 / 4; grid-column: 3 / 6;">TEST</div>
</div>


