<div class="container">
  <div class="item">One</div>
  <div class="item">Two</div>
  <div class="item">
    <ul>
    <li>Three: a</li>
    <li>Three: b</li>
    <li>Three: c</li>
    </ul>
    </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;
  align-items: flex-start;
}

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

.item ul {
  margin: 0;
  padding: 0;
  list-style: none;
}