atom.io (smaller tabs and line numbers)

atom_styles.less

// Editor 
.editor {
  .gutter {
    .line-number {
      padding: 0 0 0 0.25em;

      .icon-right {
          padding-right: 0.1em
      }
    }
  }

  .cursor {}
}

// Thinner Tabs

.tab-bar {
  height: 34px;
  padding: 0;

  .tab {
    -webkit-transform: none;
    top: 2px; line-height: 25px;

    &.active {
      height: 25px;

      &:before {
        height: 25px;
      }
    }

    &:before {
      -webkit-transform: none;
      width: 18px;
    }

    .close-icon {
      -webkit-transform: none;
      line-height: 25px;
    }

    .title {
      -webkit-transform: none;
    }
  }
}

It looks like there's a @tab-height ui variable. Is there some way to override ui variables?