edx-platform/lms/static/sass/base/_mixins.scss

// lms - utilities - mixins and extends
// ====================

// mixins - font sizing
@mixin font-size($sizeValue: 16) {
  font-size: $sizeValue + px;
  // font-size: ($sizeValue/10) + rem;
}

// mixins - line height
@mixin line-height($fontSize: auto) {
  line-height: ($fontSize*1.48) + px;
  // line-height: (($fontSize/10)*1.48) + rem;
}

// image-replacement hidden text
@mixin text-hide() {
  text-indent: 100%;
  white-space: nowrap;
  overflow: hidden;
}

@mixin vertically-and-horizontally-centered ($height, $width) {
  left: 50%;
  margin-left: -$width / 2;
  //margin-top: -$height / 2;
  min-height: $height;
  min-width: $width;
  position: absolute;
  top: 150px;
}

// sunsetted, but still used mixins
@mixin hide-text() {
  text-indent: -9999px;
  overflow: hidden;
  display: block;
}

@mixin show-hover-state() {
  opacity: 1;
}

@function em($pxval, $base: 16) {
  @return #{$pxval / $base}em;
}

// line-height
@function lh($amount: 1) {
  @return $body-line-height * $amount;
}

// ====================

// theme mixin styles
@mixin login_register_h1_style {} /* stylelint-disable-line */

@mixin footer_references_style {} /* stylelint-disable-line */

// ====================

// extends - UI - used for page/view-level wrappers (for centering/grids)
%ui-wrapper {
  @include clearfix();

  box-sizing: border-box;
  width: 100%;
}

// extends - UI - window
%ui-window {
  @include clearfix();

  border-radius: 3px;
  box-shadow: 0 1px 2px 1px $shadow-l1;
  margin-bottom: $baseline;
  border: 1px solid $light-gray;
  background: $white;
}

// extends - UI archetypes - well
%ui-well {
  box-shadow: inset 0 1px 2px 1px $shadow-l1;
  padding: ($baseline*0.75) $baseline;
}

// extends - UI - visual link
%ui-fake-link {
  cursor: pointer;
}

// extends - UI - functional disable
%ui-disabled {
  pointer-events: none;
  outline: none;
  cursor: default;
}

// extends - UI - depth levels
%ui-depth0 { z-index: 0; }
%ui-depth1 { z-index: 10; }
%ui-depth2 { z-index: 100; }
%ui-depth3 { z-index: 1000; }
%ui-depth4 { z-index: 10000; }
%ui-depth5 { z-index: 100000; }

// extends - UI - utility - nth-type style clearing
%wipe-first-child {
  &:first-child {
    margin-top: 0;
    border-top: none;
    padding-top: 0;
  }
}

// extends - UI - utility - nth-type style clearing
%wipe-last-child {
  &:last-child {
    margin-bottom: 0;
    border-bottom: none;
    padding-bottom: 0;
  }
}

// extends -hidden elems - screenreaders
%text-sr {
  // clip has been deprecated but is still supported
  clip: rect(1px 1px 1px 1px);
  clip: rect(1px, 1px, 1px, 1px);
  position: absolute;
  margin: -1px;
  height: 1px;
  width: 1px;
  border: 0;
  padding: 0;
  overflow: hidden;
  // ensure there are spaces in sr text
  word-wrap: normal;
}

// extends - ensures proper contrast for automated checkers
%a11y-ensure-contrast {
  background: $white;
  color: $black;
}

// extends - UI - removes list styling/spacing when using uls, ols for navigation and less content-centric cases
%ui-no-list {
  list-style: none;
  margin: 0;
  padding: 0;
  text-indent: 0;

  li,
  dt,
  dd {
    margin: 0;
    padding: 0;
  }
}

// extends - text - image-replacement hidden text
%text-hide {
  text-indent: 100%;
  white-space: nowrap;
  overflow: hidden;
}

// extends - text - wrapping
%text-wrap {
  text-wrap: wrap; /* stylelint-disable-line */
  white-space: pre-wrap;
  white-space: -moz-pre-wrap;
  word-wrap: break-word;
}

// extends - text - text overflow by ellipsis
%text-truncated {
  box-sizing: border-box;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

// border control
%no-border-top {
  border-top: none;
}

%no-border-bottom {
  border-bottom: none;
}

%no-border-left {
  border-left: none;
}

%no-border-right {
  border-right: none;
}

// outline
%no-outline {
  outline: none;
}

// shame-based mixins to centrally override poor styling
%shame-link-base {
  color: $link-color;

  &:hover,
  &:focus {
    color: saturate($link-color, 50%);
  }
}

%shame-link-text {
  @extend %shame-link-base;

  &:hover,
  &:focus {
    text-decoration: underline !important;
  }
}