@trousers/theme-css is an alternate theme provider which uses CSS variables under the hood. Use this package to reduce the run-time burden theming would otherwise have on your application.
It has the same API as @trousers/theme so please refer to that modules API docs for guidance.
Please note: Using CSS vars in legacy browsers such as IE 11 and older is not supported, you will need to consider using a polyfill or the base @trousers/theme package if this is a problem.