Answers for "bootstrap sm grid"

.col-12 bootstrap

.col-12{
	flex: 0 0 100%;
	max-width: 100%;
}

boostrap grid

<div class="row">
  <div class="col-9">.col-9</div>
  <div class="col-4">.col-4<br>Since 9 + 4 = 13 > 12, this 4-column-wide div gets wrapped onto a new line as one contiguous unit.</div>
  <div class="col-6">.col-6<br>Subsequent columns continue along the new line.</div>
</div>