.loading
  .loading-circle.loading-row1.loading-col3
  - for (var i = 2; i <= 4; ++i)
    div(class="loading-circle loading-row2 loading-col#{i}")
  - for (var i = 1; i <= 5; ++i)
    div(class="loading-circle loading-row3 loading-col#{i}")
  - for (var i = 2; i <= 4; ++i)
    div(class="loading-circle loading-row4 loading-col#{i}")
  .loading-circle.loading-row5.loading-col3