Simple sticky footer with less

style.less

@footer_height: 100px;

body, html {
  height: 100%;
}

.i-sticky {
  min-height: 100%;
  height: auto !important;
  height: 100%;
  margin: 0 auto -(@footer_height);
}

.footer, .i-push {
  height: @footer_height;
}