[css] Left/Right float button inside div

.test {_x000D_
  width: 60%;_x000D_
  display: inline;_x000D_
  overflow: auto;_x000D_
  white-space: nowrap;_x000D_
  margin: 0px auto;_x000D_
}

<div class='test'>_x000D_
  <div style='float: left;'>_x000D_
    <button>test</button>_x000D_
  </div>_x000D_
  <div style='float: right;'>_x000D_
    <button>test</button>_x000D_
  </div>_x000D_
</div>

.test {_x000D_
  display: flex;_x000D_
  justify-content: space-between;_x000D_
  width: 20rem;_x000D_
  border: .1rem red solid;_x000D_
}

<div class="test">_x000D_
  <button>test</button>_x000D_
  <button>test</button>_x000D_
</div>

div {_x000D_
  width: 20rem;_x000D_
  border: .1rem red solid;_x000D_
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet" />_x000D_
<div class="d-flex justify-content-between">_x000D_
  <button>test</button>_x000D_
  <button>test</button>_x000D_
</div>