Actually, css inheritance cannot be stopped with a single setting. It is defined by the entire cs structure of the page. JQuery libraries set styles to unique css classes to prevent the styles from being applied to other elements. I observed the link of your site and noticed that you've set specific jquery classes to the body of the page and the wrapping div of the page. This is the reason why the navigation will also inherit jquery styles. I wouldn't suggest applying those classes to such global elements in the html hierarchy if not needed, because this will inevitably lead to child tags inheriting those stles as well. If it's important to have those css classes, set to the body and the wrapping div, then you will have to override the styles, which are applied to the navigation and shouldn't be. The other option is to define a load order for your css styles in the Theme of your project. This is done in a LoadOrder.xml file, which practically defines how your css files will be applied on the page (their order). If the styles for the naavigation are set after the Jquery styles, they will get applied on top of the jquery styles and will have bigger weight than those styles, so practically jquery css will not override your navigation styles.
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