JSFiddle - React, Tailwind, and code Playground

HTML

<div class="section-sect1">
  <a name="CH_00001-SEC-1"></a>
  <div class="section-title">
    <span class="section-num"></span> Title</div>
  <div class="para">Text1
  </div>
  <div class="para">Text2
  </div>
</div>

CSS

.section-sect1 .para:first-letter {
 border: 1px solid;
 font-weight: bold;
 color: red;
}