JSFiddle - React, Tailwind, and code Playground
HTML
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/ui-lightness/jquery-ui.css">
<div class='container'>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
<div class='item'>item</div>
</div>
CSS
.inner-container {
border: 2px dashed orange;
}
JavaScript
$(".container .item").slice(0,17).wrapAll('<div class="inner-container"></div>')
.end().slice(17).wrapAll('<div class="inner-container"></div>');