-- integer by: 2

-- ftd.color red: red
dark: red

-- ftd.color color1: rgba(0, 128, 0, 0.35)
dark: rgba(0, 128, 0, 0.35)

-- ftd.column:
padding: 40

-- ftd.integer: $by

-- ftd.text: increment by
$on-click$: increment $by by 1

-- ftd.text: decrement by
$on-click$: decrement $by by 1

-- ftd.row foo:
integer a:
boolean b: false
$on-click$: toggle $b
$on-click$: increment $a by $by

--- ftd.integer:
value: $a
background-color if $b: $color1
color if $a == 30: $red

-- foo:
a: 20