message: modify demo: option UI
diff: margin-bottom: 1rem
  .option-list
  + .group
  + margin-bottom: 1rem
  border: 1px solid rgba(0, 0, 0, .1)
  border-radius: $radius-size-medium
  li
  height: 3.5rem
  border-bottom: 1px solid rgba(0, 0, 0, .1)
  - &.even
  + &.sub
  + font-size: $fontsize-medium
  background-color: $color-active-light-gray
  + &.first
  + box-shadow: 0 1px 1px 1px #eee inset
  + &.last
  + border-bottom: none
  +
  .demo
  @media screen and (min-width: 42rem)
  flex: 0 0 23rem
  