Removing content top margin

I have a white margin of 5px underneath my navigation bar in my Nivarna child theme.
I have edited the CSS in the editor and in the custom CSS areas.

#main {margin-top:5px; } This is what i see when i debug the browser, when i change to #main {margin-top:0px; it on the live site, the change takes effect When i make the change in the editor, it does not take effect.