add style at a calendar control

[luigi.corrias]

Someone can suggest how i can add CCS Style, from an external
files .css, at a typical asp.net 2 Calendar Control

<asp:Calendar ID="Calendar1" runat="server"
OnDayRender="Calendar1_DayRender" BackColor="White"
BorderColor="Black"
DayNameFormat="Shortest" Font-Names="Trebuchet MS ,Tahoma, Helvetica,
sans-serif;"
Font-Size="9pt" ForeColor="Black"
Height="148px" Width="177px" NextPrevFormat="FullMonth"
TitleFormat="Month">
<SelectedDayStyle BackColor="#CC3333"
ForeColor="White" />
<SelectorStyle BackColor="#CCCCCC" Font-
Bold="True" Font-Names="Trebuchet MS ,Tahoma, Helvetica, sans-serif;"
Font-Size="8pt" ForeColor="#333333"
Width="1%" />
<TodayDayStyle BackColor="#CCCC99" />
<OtherMonthDayStyle ForeColor="#999999" />
<NextPrevStyle Font-Size="8pt"
ForeColor="White" />
<DayHeaderStyle BackColor="#CCCCCC" Font-
Bold="True" Font-Size="7pt" ForeColor="#333333"
Height="10pt" />
<TitleStyle BackColor="Black" Font-
Bold="True" Font-Size="13pt" ForeColor="White"
Height="14pt" />
<DayStyle Width="14%" />
</asp:Calendar>

What can write in css sheet?

thanks

Luigi