reduce margin in space between header and nav

Hi all: I'm in need of the css syntax to eliminate a space between

the header and nav bar of a twenty fourteen wordpress blog

http://www.allcleanincmd.com


site is a wordpress twenty fourteen - static page as home page

I've elected to not use a header graphic, in favor of the 2014 featured image.

I would like to eliminate the white space below the nav bar and the space where the individual page is rendered

I've installed the Simple CSS plugin in hopes of accomplish this

I've uploaded a screen shot to drop box here:

https://www.dropbox.com/s/3iucbc3y1c...argin.JPG?dl=0

I know just enough css to break things.. some things are called "elements" others are "styles".

I know there is a syntax wherein we instruct the browser take "this thing" : and do "that"

I know there are brackets before and after...

I suspect the Simple CSS plugin eliminates my need for brackets

many thanks in advance

I don't use Wordpress or know anything about the plugin you've mentioned but learning how to use the developer toolbar to inspect an element will help you target and modify CSS live in the browser. F12 in most browsers.