CSS - Flexbox order

HTML

<ul class="flex-container">
<li class="flex-item">1</li>
<li class="flex-item">2</li>
<li class="flex-item">3</li>
<li class="flex-item">4</li>
<li class="flex-item">5</li>
</ul>

CSS

.flex-item:nth-of-type(1) { order: 3; }
.flex-item:nth-of-type(2) { order: 4; }
.flex-item:nth-of-type(3) { order: 1; }
.flex-item:nth-of-type(4) { order: 5; }
.flex-item:nth-of-type(5) { order: 2; }