JSFiddle - React, Tailwind, and code Playground

HTML

<ol class="chapter">
	<li>Apresentacao</li>
	<ol class="section">
		<li> Conteudo </li>
		<li> Programação </li>
		<ol class="subsection">
		    <li> JAVA </li>
		    <li> DOTNET </li>
	    </ol>
	</ol>
	<li>Conclusão</li>
	<ol class="section">
		<li> Agradecimentos</li>
	     <ol class="subsection">
		    <li> Família </li>
		    <li> Professores </li>
	    </ol>
	</ol>
	<li>Fim</li>
</ol>

CSS

body {
    counter-reset: chapter;
}
ol {
   list-style-type: none;
}
.chapter > li:before {
   counter-increment: chapter;
   content: counter(chapter)"."; 
}
ol.section {
    counter-reset: section;
}

ol.section > li:before { 
    content: counter(chapter)"."counter(section)" "; 
    counter-increment: section;
}

ol.subsection {
    counter-reset: subsection;
}

ol.subsection > li:before { 
    content: counter(chapter)"."counter(section)"."counter(subsection)" "; 
    counter-increment: subsection;
}