<form>
  <fieldset>  
    <label class="active">
      <input type="radio" name="class" value="container--one" class="radio" checked="checked">
      <code>stretch</code>
      <small>(default)</small>
    </label>        
    <label>
      <input type="radio" name="class" value="container--two" class="radio">
      <code>end</code>
    </label>     
    <label>
      <input type="radio" name="class" value="container--three" class="radio">
      <code>left</code>
    </label>         
    <label>
      <input type="radio" name="class" value="container--four" class="radio">
      <code>center</code>
    </label>             
  </fieldset>  
</form>

<div class="container container--one" id="container">
  <div class="item item--1">
    Item 1
  </div>
  <div class="item item--2">
    Item 2
  </div>
  <div class="item item--3">
    Item 3
  </div>  
</div>
.container--one {
  justify-items: stretch;
}

.container--two {
  justify-items: end;
}

.container--three {
  justify-items: left;
}

.container--four {
  justify-items: center;
}

/* ETC (Formatting only): */

body {
  margin: 1.5em;
  font-size: 130%;
  font-family: sans-serif;
  background: #F2F0EC;
  color: #2E2C08;
}

.container { 
  border: 10px solid #2E2C08;
  background: white;  
  padding: 1rem;
}

.item {
  margin: 0.25rem;
  padding: 0.5em;
  text-align: center;
  background: #e5e3de;
  font-weight: bold;
}

fieldset {
  border: #abab9d 1px solid;
  padding: 0;
  margin-bottom: 2em; 
}

label {
  display: inline-block;
  padding: 0.5em;
  cursor: pointer;
}

.active {
  background: #abab9d;
}

/* This pen styling */

.container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  height: 10em;  
}

.item {  
  padding: 1em;
  text-align: center;
  height: 5em;
  min-width: 5em;
}


var radios = document.querySelectorAll('.radio');
var container = document.getElementById('container');
radios.forEach(function(i){
    i.addEventListener('click', function(el){
        var clicked = el.currentTarget;
        var active = clicked.parentElement.parentElement.querySelector('.active');
        active && active.classList.remove('active');
        clicked.parentElement.classList.add('active');     
        container.className = 'container '+clicked.value;
    });
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.