"The example above highlights an INPUT element when its LABEL is focused or hove...

cleverjake on March 6, 2012 | parent | context | favorite | on: CSS4 Preview – Selectors

"The example above highlights an INPUT element when its LABEL is focused or hovered-over; the association is made by the for attribute of the label. As you can probably tell, the id is implied by the LABEL element's for attribute."