<html>
  <style>
    div.rect { width: 10px; height: 10px; display: inline-block }
  </style>
<body>
  <div style="width: 100px; border: 1px solid blue">
    <div class="rect" style="background: lime"></div
    ><div class="rect" style="background: blue; margin-left: 20px"></div>
  </div>
  <div style="width: 10px; height: 100px; border: 1px solid purple">
    <div class="rect" style="background: lime"></div>
    <div class="rect" style="background: purple; margin-top: 20px"></div>
  </div>
</body>
</html>