Keeping button states after click

Hey, I have setup a FAQ page that uses categories as a sticky nav. I have category buttons sorting content through custom code which is working great but whenever I click away from the buttons (example: anywhere else on the page) the button no longer stay bolded which is needed as my focus state.

I need these buttons to stay bolded. This is especially important on mobile as the category buttons serve as a header for the content. If anyone could help me with this it would be much appreciated!


Here is my site Read-Only: https://preview.webflow.com/preview/kats-gd-public-one?utm_medium=preview_link&utm_source=designer&utm_content=kats-gd-public-one&preview=0e01223717f13c729c5f0c6d13931308&pageId=5ef0c0266e8e1b6803a8f704&mode=preview