@extend is teh win

dashboard.sass

.report_summaries
  display: table
  width: 100%
  +mobile-only
    @extend .flat_summaries
  .report_row
    display: table-row
  .report_cell
    width: 50%
    display: table-cell
    padding: 0 10px 10px 0
    .report_summary
      border: 1px solid $grayLight
      +border-radius(3px)
      h3
        background: $grayLightest
        +smart_gradient($grayLightest)
        +border-radius(3px 3px 0 0)
        border-bottom: 1px solid $grayLight
        padding: 5px 10px
        margin-bottom: 0
        +single-text-shadow(#fff, 0, 1px, 0)
        +tablet-and-above
          font-size: $basefont + 1
        a
          display: block
          padding: 5px 0 3px 0

        .button_group
          position: relative
          z-index: 123
          float: right
          +box-shadow(none)
          margin-top: 2px
          +single-box-shadow(rgba(#fff, .5), 0, 1px, 0)
          .b
            a
              padding: 5px 10px
              line-height: 1em
              height: auto
      .report_previews
        // padding: 10px
        .preview
          display: none
          min-width: 100px
          min-height: 100px
          &.active
            display: block
          svg
            
            height: 300px
            +mobile-only
              height: 200px

.flat_summaries
  display: block
  .report_row
    display: block
  .report_cell
    display: block
    width: 100%
    margin-bottom: 10px
    padding: 0
    .report_summary
      .report_previews
        svg
          width: 100%