Manufacturer.aspx -> ProductsInGrid.ascx -> ProductBox1.ascx :: css (import from root.masterpage) dont influence on page

Hi all

i import css file from root.masterpage,
so i changed template of productbox1.ascx, however it doesn't influence on the page.

---------------------
css file:
.thumbnail span{
........
position: absolute;
......
}

----------------------

this is a part of code from productbox1.ascx:

<asp:HyperLink class="thumbnail" ID="lnkImageProduct" runat="server">
          <asp:Image ID="hlImageLink" runat="server" />
          <span>
                  <asp:Image ID="imgPopup" runat="server" />
                  <div class="clear"></div>
                  <asp:Literal runat="server" ID="lShortDescription"></asp:Literal>
           </span>
</asp:HyperLink>

-----------
it's work with RecentlyAddedProducts.ascx, but doesn't work with Manufacturer.aspx -> ProductsInGrid.ascx

how can i fix this case...

pls help me!

Thanks

i had answer for myself :D

i put css code into style.css file, it work.

however i don't know why it doesn't work with separate file css