Hi you can do it i give you example
css
body{
counter-reset:section;
}
div{
margin-top:10px;margin-left:10px;
}
.numercal {
counter-reset:subsection;
font-weight:bold;
}
.numercal:before{
counter-increment:section;
content:"Section " counter(section) ". ";
font-style:italic;
color:red;
}
.numercal-no:before{
counter-increment:subsection;
content:counter(section) "." counter(subsection) " ";
}
HTML
<div>
<p class="numercal">Demo Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
</div>
<div>
<p class="numercal">Demo Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
</div>
<div>
<p class="numercal">Demo Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
<p class="numercal-no">Sub Text here</p>
</div>
Live demo click here http://jsfiddle.net/rohitazad/Xwm3C/1/
Now more about this go to this site http://reference.sitepoint.com/css/counter-increment
http://www.w3.org/wiki/CSS/Properties/counter-increment