Stack

The component for putting things on top of other things

A stack is a collection of elements of the same type, stacked on top of each other with the margins between them removed. It is intended for grouping elements with a visible background, such as buttons, as in this example. (See also below for an example with an accordion).
<div class="stack">
  <button>First button</button>
  <button>Second button</button>
  <button>Third button</button>
</div>