1，文本行数限制

.add-text-row-limit(@row) {
  overflow: hidden;
  text-overflow: ellipsis;
  .create();

  .create() when (@row > 1) {
    display: -webkit-box;
    -webkit-line-clamp: @row;
    -webkit-box-orient: vertical;
  }

  .create() when (@row = 1) {
    white-space: nowrap;
  }
}

1.1，使用

p {
  .add-text-row-limit(1);
}

2，三角箭头

.add-triangle-arrow(@position, @size, @bk-color, @arrow-direction: @position) {
  position: absolute;
  content: '';
  border: @size solid transparent;
  .create();

  // 上下
  .create() when (@position = top) {
    left: 50%;
    top: 0;
    transform: translate(-50%, -100%);
  }

  .create() when (@position = bottom) {
    left: 50%;
    bottom: 0;
    transform: translate(-50%, 100%);
  }

  .create() when (@arrow-direction = top) {
    border-bottom-color: @bk-color;
    border-top: 0;
  }

  .create() when (@arrow-direction = bottom) {
    border-top-color: @bk-color;
    border-bottom: 0;
  }

  // 左右
  .create() when (@position = left) {
    top: 50%;
    left: 0;
    transform: translate(-100%, -50%);
  }

  .create() when (@position = right) {
    top: 50%;
    right: 0;
    transform: translate(100%, -50%);
  }

  .create() when (@arrow-direction = left) {
    border-right-color: @bk-color;
    border-left: 0;
  }

  .create() when (@arrow-direction = right) {
    border-left-color: @bk-color;
    border-right: 0;
  }
}

2.1，使用：

div::after {
  .add-triangle-arrow(
    箭头的位置: left | right | bottom | top,
    箭头大小: 5px,
    箭头颜色: blue,
    箭头方向?: left | right | bottom | top,
  );
}

3，媒体查询

@pad-screen: 768px;
@iPad-pro-screen: 1024px;
@screenDeviation: 0.1;

.phone(@content) {
  @media screen and (max-width: (@pad-screen - @screenDeviation)) {
    @content();
  }
}

.phoneOrPad(@content) {
  @media screen and (max-width: @iPad-pro-screen) {
    @content();
  }
}

.ipad(@content) {
  @media screen and (min-width: @pad-screen) and (max-width: @iPad-pro-screen) {
    @content();
  }
}

.notIpad(@content) {
  @media screen and (max-width: (@pad-screen - @screenDeviation)), screen and (min-width: (@iPad-pro-screen + @screenDeviation)) {
    @content();
  }
}

.pcOrPad(@content) {
  @media screen and (min-width: @pad-screen) {
    @content();
  }
}

.pc(@content) {
  @media screen and (min-width: (@iPad-pro-screen + @screenDeviation)) {
    @content();
  }
}

3.1 使用

div {
  .phone({
    font-size: 15px;
  });
}