message: Clean channel block group style
diff: .ChannelBlockGroup
  width 100%
  border-top 1px solid bordergray
  - display flex
  padding (unit * 2) 0
  - justify-content center
  + &__inner
  + margin 0 auto
  + display flex
  + justify-content flex-start
  - @media (min-width:(block_width_mar * 3) + 20) and (max-width:(block_width_mar * 4) + 20)
  - .Block:nth-of-type(1n+4)
  - display none
  - @media (min-width:(block_width_mar * 2) + 20) and (max-width:(block_width_mar * 3) + 20)
  - .Block:nth-of-type(1n+3)
  - display none
  - @media (min-width:(block_width_mar * 1) + 20) and (max-width:(block_width_mar * 2) + 20)
  - .Block:nth-of-type(1n+2)
  + for i in (1..4)
  + @media (min-width:(block_width_mar * i) + 20) and (max-width:(block_width_mar * (i + 1)) + 20)
  + &__inner
  + width (block_width_mar * i) + 20
  + .Block:nth-of-type(1n+{i+1})
  display none
  