JSFiddle - React, Tailwind, and code Playground

HTML

<h5>2-ая страници</h5>
<div><span>Back</span><span>1</span><b>2</b><span>3</span><span>Next</span></div>

<h5>Первая страници</h5>
<div><b>1</b><span>2</span><span>3</span><span>Next</span></div>

<h5>Последняя страници</h5>
<div><span>Back</span><span>1</span><span>2</span><b>3</b></div>

CSS

div {color:green;}
div > b {color:blue;}
div span:last-child,
div span:first-child {
    color: red;
}