JSFiddle - React, Tailwind, and code Playground

HTML

<div class="header"><span class="dick">ХУЙ</span></div>

CSS

.dick{
position:relative;
z-index:2;
display:inline;
font-size:50px;
font-family:arial;
color:red;
}

.dick:after{
position:relative;
content:"";
display:block;
border-bottom:5px solid blue;
z-index:1;
top:-30px;
}