Hi,
You can surround the literal with span tag and use class attribute to specify the CSS class name. Please find an example below.
<span class="your class">
<asp:Literal runat="server" ID="literal1" Text="some text"/>
</span>
Where your class is name of CSS class that you may need to specify in your CSS. You can find more details about CSS stylesheets in our Developer's guide:
http://devnet.kentico.com/docs/devguide/index.html?css_overview.htm
Best Regards,
Pavel Knotek