JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li class="a">First</li>
    <li class="a">Second</li>
    <li class="a">Third</li> 
</ul> 
<ul>
    <li class="a">First</li>
    <li class="a">Second</li>
    <li class="a">Third</li> 
</ul> 
<ul>
    <li class="a">First</li>
    <li class="a">Second</li>
    <li class="a">Third</li> 
</ul>

CSS

ul li:last-of-type {
    color: red;
}