make more useful for elm, better styling

more useful for elm:
  results printed like an elm function call for easy copy and paste
  hsl uses values elm's `hsl` function uses: radians for hue, saturation
  and lightness as fractions between 0 and 1

better styling:
  layout less dependent on window dimensions; should look reasonable for
  more window sizes now
  show hints for the field on bad/incomplete user input
  style fields a bit