[balinor]

Replace this:

<SPAN class=>
{if $product.fulldescr ne ""}{$product.fulldescr}{else}{$product.descr}{/if}
</SPAN>

with this:

<SPAN class="description">
{if $product.fulldescr ne ""}{$product.fulldescr}{else}{$product.descr}{/if}
</SPAN>

now go into skin1.css, and add this:

.description {font-size: 12px;}

Replace 12px with whatever size you want the description text to appear. If it doesn't work, try replacing the span tag with a div tag.