<div class="container">
  <div class="item">One</div>
  <div class="item">Two Two</div>
  <div class="item push-right">Three Three Three</div>
  <div class="item">Four Four Four Four</div>
</div>
body {
  padding: 20px;
  font: 1em Helvetica Neue, Helvetica, Arial, sans-serif;
}

* {box-sizing: border-box;}

.container {
  border: 5px solid rgb(111,41,97);
  border-radius: .5em;
  padding: 10px;
  display: flex;
  margin: 1em;
}

.push-right {
  margin-left: auto;
}

.item {
  padding: 10px;
  background-color: rgba(111,41,97,.3);
  border: 2px solid rgba(111,41,97,.5);
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.