less 循环生成间距样式 margin padding

@list: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 , 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49,50;
each(@list, {
  .m-r-@{value} {
    margin-right: @value * 1px;
  }
  .m-t-@{value} {
    margin-top: @value * 1px;
  }
  .m-b-@{value} {
    margin-bottom: @value * 1px;
  }
  .m-l-@{value} {
    margin-left: @value * 1px;
  }
  .p-t-@{value} {
    padding-top: @value * 1px;
  }
  .p-b-@{value} {
    padding-bottom: @value * 1px;
  }
  .p-r-@{value} {
    padding-right: @value * 1px;
  }
});