JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <img src="" title="hello world"/>
</div>

<div>
    <p>hello world</p>
</div>

<div>
    <h4>hello world</h4>
</div>

CSS

div:after {
    content: "";
    display: block;
    border-bottom: 2px solid red;
}
p + div:after {
    content: "";
    display: block;
    border-bottom: 2px solid blue;
}