To achieve responsive layouts, the UI Library relies on the Bootstrap Grid System.

The basics of responsiveness are achieved by using the following construct:

<div class="container">
  <div class="row">
    <div class="col-sm-6">
      col-sm-6
    </div>
    <div class="col-sm-6">
      col-sm-6
    </div>
  </div>
</div>

We generally use `col-sm-xx` for the columns, but if we want the columns to not collapse at the smallest (mobile) size, we use `col-xs-xx`. This retains the column definitions at the smallest breakpoint. For more details, see the Bootstrap Grid System documentation linked above.