Hello,
we added styling to checkout fields via elementor general styling options.
The styles are applied to most of all fields, but not to dropdown fields in checkout.
Switched to storefront and switched to hello theme and its working.
Re-enabled your theme: The fontsize is much larger and looking very strange.
We contact elementor and they told us we have to contact the theme developer.
Sure, we can fix it by custom css. But the theme shoud apply styling options from elementor to make it smart in working time without custom css for same problems in each new theme setup with this theme.
Check also attached screenshot please.
BR
Tommy