JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
  </head>
  <body>
    <h1>
      <span class="opened">test අනතුරුව</span>
      <br>
      <span class="closed">test</span>
    </h1>
  </body>
</html>

CSS

.opened::before {
    display: inline-block;
    content: "▼";
    width: 30px;
}

.closed::before {
    display: inline-block;
    content: "▶";
    width: 30px;
}