JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <span>This span is the only child of its father</span>
</div>
<br>
<div>
    <span data="visible">This span is one of the two children of its father</span>
    <span data="visible">This span is one of the two children of its father</span>
    <span data="visible">This span is one of the two children of its father</span>
    <span data="visible">This span is one of the two children of its father</span>
</div>

CSS

span:not(nth-child(1n + 1))
{
    color:red;
}