<div class="container">
  <div class="item">Two words</div>
  <div class="item">Now three words</div>
  <div class="item">
    This flex item has a lot of content and so it is going to need more space in the flex container.
    </div>
</div>

body {
  padding: 20px;
  font: 1em Helvetica Neue, Helvetica, Arial, sans-serif;
}

* {box-sizing: border-box;}

p {
  margin: 0 0 1em 0;
}

.container {  
  border: 5px solid rgb(111,41,97);
  border-radius: .5em;
  padding: 10px;
  display: flex;
  width: 400px;
}

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