-- ftd.color red: red
dark: red
-- string current: one
-- ftd.text: $current
-- ftd.row:
--- ftd.text: One
padding: 10
$on-click$: $current = one
color if $current == one: $red
--- ftd.text: Two
padding: 10
$on-click$: $current = two
color if $current == two: $red
--- ftd.text: Three
padding: 10
$on-click$: $current = three
color if $current == three: $red