JSFiddle - React, Tailwind, and code Playground

HTML

<div>
  <a href="#"><span>Inside Brackets</span></a>
</div>

CSS

body {
  font-family: Calibri;
  font-size: 20px;
  padding: 10px;
}

a {
  color: #213999;
  font-weight: 500;
  -webkit-transition: color 0.2s;
  transition: color 0.2s;
  transition: transform 0.2s;
  display: inline-block;
  text-decoration: none;
  position: relative;
  padding: 0 0.25em;
}

a:hover {
  color: #d04c3f;
}

a::before,
a::after {
  position: absolute;
  top: 0;
  font-weight: 100;
  font-size: 150%;
  line-height: 1;
  opacity: 0;
  -webkit-transition: opacity 0.2s, -webkit-transform 0.2s;
  transition: opacity 0.2s, transform 0.2s;
}

a::before {
  left: -0.1em;
  content: '[';
  -webkit-transform: translateX(-100%);
  transform: translateX(-100%);
}

a::after {
  right: -0.1em;
  content: ']';
  -webkit-transform: translateX(100%);
  transform: translateX(100%);
}

a:hover::before,
a:hover::after {
  opacity: 1;
  -webkit-transform: translateX(0);
  transform: translateX(0);
}