.site-shell
  --shell-gap: var(--gap-page)
  --shell-edge-inset: 16px
  --shell-topbar-top: 0px

.site-shell[data-regions~='topbar']
  --shell-sticky-offset: var(--shell-topbar-height)
  --shell-topbar-bottom: var(--shell-topbar-height)

.ui-surface
  appearance-card-surface()

.site-region--topbar.ui-surface
  top: 0
  width: 100%
  border-radius: 0

.site-region--leftbar .ui-surface
  background: var(--card)

.site-region--leftbar
  .brand-navigation__back
    background: var(--block-border)
    box-shadow: none
  .search-wrapper > .search-form:before
    background: var(--text-meta)

appearance-standard-interactions()
appearance-standard-prose()
appearance-card-listing-nav()