How do I change the size of the UNavigationMenu buttons?

  <UNavigationMenu
  :items="items"
  orientation="vertical"
  class="w-full mb-auto"
  :ui="{
    item: 'text-xs'
  }"
/>

  <UNavigationMenu
  :items="items"
  orientation="vertical"
  class="w-full mb-auto"
  :ui="{
    item: 'text-xs'
  }"
/>