.small { grid-column: 1 / span 2; grid-row: 1 / span 2; }
The code creates a grid with five columns and 75 rows. The grid has a gap of 5 pixels, and the grid template columns are repeated every 100 pixels, with a minimum size of 1 pixel and a maximum size of 100 pixels. The grid has a flow of dense.
.container {
display: grid;
grid-gap: 5px;
grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
grid-auto-rows: 75px;
grid-auto-flow: dense;
}
.horizontal {
grid-column: span 2;
}
.vertical {
grid-row: span 2;
}
.big {
grid-column: span 2;
grid-row: span 2;
}