gistfile1.txt

[width] = 10

div {
  [width] = 20        # All variables are resolved through scope, so can be redefined locally
  
  width: $width       # bind to variable once (doesnt listen for future changes)
  width: [width]      # equasion (observes width)
  width: (div)[width] # only binds by selector (observes)
}