<!DOCTYPE html>
<html>
<link href="resources/flexbox.css" rel="stylesheet">
<style>
  .a {
    flex: none;
    width: 30px;
    background: salmon;
  }
</style>
<body>
  <div class="flexbox justify-content-space-around">
    <div class="a"></div>
  </div>

  <div class="flexbox">
    <b>foo</b><b>bar</b>
  </div>