I started using the datepicker from jquery. I noticed that by default it uses the provided theme in /core/assets/vendor/jquery.ui/themes/base/theme.css and /core/assets/vendor/jquery.ui/themes/base/datepicker.css.
There seems to be only the base theme available.
How can I create my own theme and tell drupal to use my jquery ui theme?
Ideally I would like to be able to select the jquery ui theme from a custom Drupal theme. This way I would be able to change automatically the jquery ui theme from the Appearance menu by changing the theme and use the existing overriding system if I have a sub theme inheriting from that theme.