按钮

<button class="btn btn-primary">主要按钮</button>
      <button class="btn btn-success">成功按钮</button>
      <button class="btn btn-info">信息按钮</button>
      <button class="btn btn-warning">警告按钮</button>
      <button class="btn btn-danger">危险按钮</button>


.btn{
  height: 60px;
  line-height: 30px;
  text-align: center;
  color: #fff;
  padding: 20px 50px;
  margin:  5px;
  border: none;
}
@btnNames: primary, success, info, warning, danger;
@btnColors: #409EFF, #67C23A,#909399,#E6A23C,#F56C6C;
.loop(@i) when (@i<=length(@btnNames)){
  @btnName:extract(@btnNames,@i);
  @btnColor:extract(@btnColors,@i);
  .btn-@{btnName}{
    background: @btnColor;
  }
.loop(@i + 1);
}
.loop(1);