Calendar control font size issue - everything works but not the font-size ?!

Hi,
I've created a web part and I have Calendar control in it.
All properties of Calendar control work as expected, but not the font size.
No matter what ("Large", "22pt") and where (on Calendar control, in DayStyle, SelectedDayStyle, in .cs in DayRender, using CssClass) I specify in font-size it looks correct in Visual Sutdio, but not in SharePoint.
In SharePoint the only one font-size that works correct is DayHeaderStyle (?!)
All other changes to the font-size have no effect in SharePoint - letters still look small. I just want to create big calendar that's all.
All other properties (font-bold, font-italic, colors etc) work. But not the font-size.
Very weird. I am pretty sure I am missing something.
Any comments will be highly appreciated!
Thanks,
Jack
PS:
ascx
            <asp:Calendar ID="Calendar1" runat=" ...