States
Many interface elements appear in different states.
ViUR Ignite CSS tries to consolidate recurring state types,
like .is-active, .is-disabled, .is-loading etc.
Some of these states have native pseudo class or attribute counterparts
— :active, :disabled
— or WAI-ARIA states and properties
— [aria-busy=true], [aria-disabled=true].
These attributes are supported as well and in most cases recommended.