// 对勾
._icon-hook(@color, @size) {

    .getSize(@size) when (length(@size) = 1) {
        @pattern_size: @size;
        @pattern_thickness: round((@size * .1 / 2)) * 2;
    }
    .getSize(@size) when (length(@size) = 2) {
        @pattern_size: extract(@size, 1);
        @pattern_thickness: extract(@size, 2);
    }
    .getSize(@size);

    .inline-block();
    vertical-align: middle;
    width: @pattern_size;
    height: @pattern_size;
    &:before {
        content: '';
        display: block;
        width: 40%;
        height: 80%;
        margin-top: -10%;
        margin-left: 25%;
        border-right: solid @pattern_thickness @color;
        border-bottom: solid  @pattern_thickness @color;
        .rotate(45deg);
    }
}
.icon-hook(@size: 30px) when (isnumber(extract(@size, 1))) {
    ._icon-hook(#666, @size);
}
.icon-hook(@color, @size: 30px) when (iscolor(@color)) {
    ._icon-hook(@color, @size);
}