How to edit main.css

I’ve set up a child theme in ving which handles style.css perfectly well. However, quite a bit of your styling is handled by main.css. The problem is that styles.css loads before these – not afterward – so any changes I make to header size, font colour etc in style.css is overridden by main.css. Other than manually editing main.css, how can I get ving to prioritise style.css ?
Thanks if you can help