thumbnail x 4, , one column can fill in 3 thumbnail, the 4th one go under and fill in rest of the space (without adding new class).
.tile {
max-width: 350px;
display: grid;
grid-template-columns: repeat(auto-fill, minmax(95px, 1fr));
grid-column-gap: 10px;
grid-row-gap: 10px;
}
.thumbnail {
padding: 20px;
height: auto;
background-color: #ff0099;
color: #fff;
}
<div class="item tile">
<div class="thumbnail">Grid - Thumbnail #1</div>
<div class="thumbnail">Grid - Thumbnail #2</div>
<div class="thumbnail">Grid - Thumbnail #3</div>
<div class="thumbnail">Grid - Thumbnail #4</div>
</div>