How to change styles for built in community website
I am new to AEM and I have created a Community website using the Communities functionality in AEM. Now I need to customise some of the styles, but I am not able to find the CSS files associated with it. Main things I need to change is the header navigation colour and some font sizes. Is there any option to overwrite the styles ? I am running AEM on my local machine and using the default bootstrap theme. My site path is /content/sites/my-community/en/ . The default quickstart install already has a community called We-Retail, but I am not sure how it is styled.