JSFiddle - React, Tailwind, and code Playground

HTML

<span id="aniNa" class="headertext">Какой-то текст</span>

SCSS

#aniNa{
//    border-right: 2px solid red;
    
}
.headertext{
    
    display: inline-block;
    color: red;
    font-family: cursive;
    font-size: 30px;
    padding: 15% 3% 0% 3%;  

    position: relative;

    &::after {
      content: '';
      position: absolute;
      right: 0;
      bottom: 0;
      width: 2px;
      height: 36px;
      background: red;
    }
}