Valo is an evolving design system foundation for modern web applications, used by Vaadin Elements.
If you just want Valo style UI components, you can use Vaadin Elements directly, such as vaadin-text-field, vaadin-button or vaadin-grid. You can install those using Bower as well.
To start using the Valo styles you need to install the vaadin-valo-styles package using Bower.
Import and include the global style modules to make your application use Valo styles: