JSFiddle - React, Tailwind, and code Playground

HTML

<p><b>Note:</b> IE8 supports these properties only if a !DOCTYPE is specified.</p>

<h1>HTML tutorials</h1>
<h2>HTML Tutorial</h2>
<h2>XHTML Tutorial</h2>
<h2>CSS Tutorial</h2>

<h1>Scripting tutorials</h1>
<h2>JavaScript</h2>
<h2>VBScript</h2>

<h1>Heading </h1>
<h2>One </h2>
<h2>Two</h2>

CSS

body {counter-reset:section;}
h1 {counter-reset:subsection;}
h1:before
{
counter-increment:section;
content:"Section " counter(section) ". ";
    font-weight:bold;
}
h2:before 
{
counter-increment:subsection;
content:counter(section) "." counter(subsection) " ";
}