[MoonDog]

vahidnia,

Search for this code in the skin1/skin1.css file.
This is what your looking for to change the font styles of the subcategories.

 
/*
 Items style
*/
.ItemsList {
 COLOR: #003834;
 FONT-WEIGHT: bold;
}
.ItemsListDisabled {
 COLOR: #909090;
}
A.ItemsList:link {
 COLOR: #330000;
 TEXT-DECORATION: none;
}
A.ItemsList:visited {
 COLOR: #330000;
 TEXT-DECORATION: none;
}
A.ItemsList:hover {
 COLOR: #330000;
 TEXT-DECORATION: underline;
}
A.ItemsList:active {
 COLOR: #330000;
 TEXT-DECORATION: none;
}

Since the font size is inherited, and you want a different size font. Then all you do is just insert the font size you want into the .ItemsList class.
Example: you want to change to font size to 16 px. All you do is insert this code:

FONT-SIZE: 16px;

into the .ItemsList class above. So that your code will now look like this:

 
.ItemsList {
 COLOR: #003834;
 FONT-SIZE: 16px;
 FONT-WEIGHT: bold;
}

And that's it.

- MoonDog -