Override CSS, need further info

Hi, I have read the http://docs.wpgeodirectory.com/customizing-your-style/ and I’m trying to change some css properties of GDF Modern through function Code->Override Css but maybe I’m missing something. For example via Chrome/Inspector I located the css part that I like to change:

#geodir_content,
#gd-sidebar-wrapper {
	padding: 30px 40px;
}

I like to reduce the padding, so I put in field Css Override the following code:

#geodir_content,gd-sidebar-wrapper {
	padding: 3px 5px;
	
}

and saved, but nothing changed refreshing the front page.
Also tried with

.geodir_content,gd-sidebar-wrapper {
	padding: 3px 5px;
	
}

but with no success. Is something wrong with my steps?
I’d prefer use Override CSS instead changind directly the style.css in order to avoid overwrite when the theme will be updated.

Another example

.geodir-onethird, #geodir_content, #gd-sidebar-wrapper {
background: #fff;
border: none;
border-radius: 0;
}

I’d like to show the border: so I have to copy it into Override Css without the line

border: none;

?

Thank you for the help in understing how it works