JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>First</li>
    <li>Second</li>
    <li>Third</li>
     <li>Third</li>
     <li>First</li>
    <li>Second</li>
    <li>Third</li>
     <li>Third</li>
</ul>

CSS

ul {
    margin:0px;
    padding:0px;
    list-style:none;
    width:100%;
}

li {
    float:left;
    text-align:center;
    box-shadow:#000 0px 0px 0px 1px inset;
}

JavaScript

var count = 0;

$('li').each(function(){
    count++;
});

$('li').css('width', $('ul').width()/count);