[Plugin: WP-RecentComments] css classes for displayed items

is there a css class for each block ?
because i’d like to change the margin e.g. the padding to get more space between the listed comments.

i’ve tried all variations with .rc_item .widget_recentcomments and such and further but i had no luck.

thanks

ps:

actually (not good):

-1.comment
-2.comment
-3.comment
-4.comment

what i need is more space between those items (good):

-1.comment
I
-2.comment
I
-3.comment
I
-4.comment