Could you modify the css of blocks in region?

First of all, the Kanji is a very nice theme! I like it!

I am using it as my default theme, and I wish the blocks in every region can be modified to center-aligned. In addition to the positions, if the background color of block can be modified to transparent, and the margins or borders should be adjusted as the content in the block automatically? Because if I just type in few texts, the margin or border of the block is still very big.

Thanks a lot, Donny Carette!