I've been building a "programming" language for UI designers, and I had no idea how hard it would be to make a language feel simple. I have no experience in this area, so I'm just trying to make it feel as if it could follow naturally from verbal speech:

  style box
    fill: red
    width: when $size
      is small: 10px
      is medium: 20px
      is large: 30px
    height: when $size
      is small: 10px
      is medium: 20px
      is large: 30px