<style type="text/css">
h3:before{
content : counter(section) ")";
counter-increment: section;
counter-reset : subsection;
}
h4:before{
content : counter(section) "-" counter(subsection);
counter-increment : subsection;
}
.initsection{ counter-reset : section }
.initsubsection{ counter-reset : subsection; }
</style>
<div class="initsection">
<h3 class="initsubsection">Titre 1</h3>
<h4>Titre 1.1</h4>
<h4>Titre 1.2</h4>
<h3 class="initsubsection">Titre 2 </h3>
<h4>Titre 2.1</h4>
<h4>Titre 2.2</h4>
</div>