Is there a place where Tribe.so community owners share custom themes that they created for Tribe? That would be cool because I don't know css.

Hi Jeff.

You can find Q&As related to the CSS under the CSS Topic Page37. 

Please be advised that the Q&As are shared with our customers. Therefore, some of the suggested codes might not be 100% functional, as the Tribe team does not provide the services to review the custom CSS, JS, or HTML codes.