Zesty: customizing the calendar at the bottom

[carisma_sensei]

Hi, i'm working with Zesty right now and i was wondering if you could help me out ^^
I'm having problems customizing the calendar that appears at the bottom of the layout. I have tried several things but i can't get to change the colour of the numbers (1, 2 etc) and the blue background on the day with posts, etc. I'm new to Zesty and the base stylesheet doesn't seem to help very much with this. So if you could help me out telling me how to customize this part of the stylesheet, i would be very happy xD

Thanks in advance!