Modify body top margin in Twenty Twelve

Where did you make your modifications?

+1 for using a custom css plugin;
just remember before you make edits to the templates to create a child theme; https://codex.www.ads-software.com/Child_Themes

there is also a top margin on the .main-navigation style; reduce that:

.main-navigation { margin-top: 0; }

and further padding in .site-header …

using a browser inspection tool helps to find out where these things get formatted.

I made the modifications through an add css plugin. I just also added
.main-navigation { margin-top: 0; } as well and still nothing…

Thanks for your help.

Try also,

.site-header {
    padding: 0;
}

that helped a little. thanks!

In the theme the padding is also listed like this:

padding: 24px 0;
padding: 1.714285714rem 0;

for almost all elements. What are the two different paddings referring to?

Thanks,
Zoe

rem (unit of measure) isn’t read by all browsers, so the px is there as a fallback for those browsers that don’t.

The notes at the top of the theme’s style.css file explain more about rem if you’re interested.

I’ve got it all worked out thanks for your help.