@nbsp: '\00A0';

/* !clear (on float wrapper) */
.clear(@clear: both) {
  & {
    *zoom: 1;
  }
  &:after {
    clear: @clear;
    content: @nbsp;
    display: block;
    height: 0;
  }
}

/* !collapse margins */
.margin-collapse() {
  &:before, &:after {
    content: @nbsp;
    display: block;
    height: 1px;
  }
  &:before { margin-bottom: -1px }
  &:after  { margin-after:  -1px }
}
.margin-collapse(top) {
  &:before {
    content: @nbsp;
    display: block;
    height: 1px;
    margin-bottom: -1px;
  }
}
.margin-collapse(bottom) {
  &:after {
    content: @nbsp;
    display: block;
    height: 1px;
    margin-after: -1px;
  }
}