Part of the Apsides project, see https://apsides.web.app. Documentation available at https://apsides.web.app/ui.
The Core components package provides you with the all the building blocks you need to construct your UI and the CSS classes to customize it to your liking. The look and feel is based on Material Design, for a modern flat look. All styles are based on emunits, using integer multiples for constant sizing. Native elements are sparely modified, increasing compatibility with foreign UI components.
This is not a UI framework. Only basic building blocks, such as buttons, input fields and progress bars are included. But with the provided CSS classes and variables, it is not hard to design new components to fit the style. The library also provides many hooks, allowing the interop between Vue reactivity and the DOM.