JSFiddle - React, Tailwind, and code Playground

HTML

<h3>Test Border</h3>
<div class="underline"></div>

CSS

h3 {
  font-size: 26px;
  color: #000 !important;
  max-width: 90px;
  display: inline-block;
  padding-bottom: 15px;
  width: 8%;
}

.underline {
  display: inline-block;
  border-bottom: 1px solid #c6bcb6;
  width: 90%;
}