discourse/app/assets/stylesheets/foundation/helpers.css.scss

// --------------------------------------------------
// Generic helper classes
// --------------------------------------------------

// Floats
// --------------------------------------------------

.pull-left {
  float: left;
}

.pull-right {
  float: right;
}

// Element visibility
// --------------------------------------------------

.show {
  display: block;
}

.hide,
.hidden {
  display: none;
}

.invisible {
  visibility: hidden;
}

// Affix
// --------------------------------------------------

.affix {
  position: fixed;
}

// Contain floats
// --------------------------------------------------

.clearfix {
  &:before,
  &:after {
    display: table;
    content: " ";
  }
  &:after {
    clear: both;
  }
}

// Image replacement
// --------------------------------------------------

.hide-text {
  border: 0;
  background-color: transparent;
  overflow: hidden;
  &:before {
    display: block;
    width: 0;
    height: 150%;
    content: "";
  }
}