How to style the drop-down filters

Hello everyone!

Could you please help me? We are creating a career website and we faced an impossibility to style the filters of the vacancies list (please see Home page → open positions section. )
It looks like this

instead of this

Can the filters lists be styled somehow?

Thank you so much for your advice!

Here is my site Read-Only: [LINK]1
(how to share your site Read-Only link)