[support] css files

[Roger]

I'm debuging and trying to modify the calendar css because the little 
blue info field is too small to display sufficient info.

Firebug shows <div class="calendar monthview"> and the style  allows me 
to modify width and height of the blue display field.
But
the url 
/sites/default/files/css/css_TuUcIk9BkwT2jDjJe_6dJMP9rOL2wZwiKQmxadx5Vvc.css
shows dozens of files in the /css folder.

Are these  temporary files generated each time a display request is made?
Where is the real calendar css  that I can change to permanently display 
my alterations to width and height for the info field?
Thanks in advance
Roger