edx-platform/xmodule/css/video/accessible_menu.scss

$a11y--gray: rgb(127, 127, 127);
$a11y--blue: rgb(0, 159, 230);
$a11y--gray-d1: shade($gray, 20%);
$a11y--gray-l2: tint($gray, 40%);
$a11y--gray-l3: tint($gray, 60%);
$a11y--blue-s1: saturate($blue, 15%);

%use-font-awesome {
  font-family: FontAwesome;
  -webkit-font-smoothing: antialiased;
  display: inline-block;
  speak: none;
}

.a11y-menu-container {
  position: relative;

  &.open {
    .a11y-menu-list {
      display: block;
    }
  }

  .a11y-menu-list {
    @extend %ui-depth3;

    top: 100%;
    margin: 0;
    padding: 0;
    display: none;
    position: absolute;
    list-style: none;
    background-color: $white;
    border: 1px solid #eee;

    li {
      @extend %ui-fake-link;

      margin: 0;
      padding: 0;
      border-bottom: 1px solid #eee;
      color: $white;

      a {
        display: block;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
        color: $a11y--gray-l2;
        font-size: 14px;
        line-height: 23px;

        &:hover,
        &:focus {
          color: $a11y--gray-d1;
        }
      }

      &.active {
        a {
          color: $a11y--blue;
        }
      }

      &:last-child {
        box-shadow: none;
        border-bottom: 0;
        margin-top: 0;
      }
    }
  }
}


// Video track button specific styles

.video-tracks {
  .a11y-menu-container {
    display: inline-block;
    vertical-align: top;
    border-left: 1px solid #eee;

    &.open {
      > a {
        background-color: $action-primary-active-bg;
        color: $very-light-text;

        &::after {
          color: $very-light-text;
        }
      }
    }

    > a {
      @include transition(all $tmg-f2 ease-in-out 0s);
      @include font-size(12);

      display: block;
      border-radius: 0 3px 3px 0;
      background-color: $very-light-text;
      padding: ($baseline*0.75) ($baseline*1.25) ($baseline*0.75) ($baseline*0.75);
      color: $a11y--gray-l2;
      min-width: 1.5em;
      line-height: 14px;
      text-align: center;
      overflow: hidden;
      text-overflow: ellipsis;

      &::after {
        @extend %use-font-awesome;

        content: "\f0d7";
        position: absolute;
        right: ($baseline*0.5);
        top: 33%;
        color: $lighter-base-font-color;
      }
    }

    .a11y-menu-list {
      right: 0;

      li {
        font-size: em(14);

        a {
          border: 0;
          display: block;
          padding: lh(0.5);
          overflow: hidden;
          text-overflow: ellipsis;
          white-space: nowrap;
        }
      }
    }
  }
}


.contextmenu,
.submenu {
  @extend %ui-depth5;

  border: 1px solid #333;
  background: $white;
  color: #333;
  padding: 0;
  margin: 0;
  list-style: none;
  position: absolute;
  top: 0;
  display: none;
  outline: none;
  cursor: default;
  white-space: nowrap;

  &.is-opened {
    display: block;
  }

  .menu-item,
  .submenu-item {
    border-top: 1px solid $gray-l3;
    padding: ($baseline/4) ($baseline/2);
    outline: none;

    & > span {
      color: #333;
    }

    &:first-child {
      border-top: none;
    }

    &:focus {
      background: #333;
      color: $white;

      & > span {
        color: $white;
      }
    }
  }

  .submenu-item {
    position: relative;
    padding: ($baseline/4) $baseline ($baseline/4) ($baseline/2);

    &::after {
      content: '\25B6';
      position: absolute;
      right: 5px;
      line-height: 25px;
      font-size: 10px;
    }

    .submenu {
      display: none;
    }

    &.is-opened {
      background: #333;
      color: $white;

      & > span {
        color: $white;
      }

      & > .submenu {
        display: block;
      }
    }

    .is-selected {
      font-weight: bold;
    }
  }

  .is-disabled {
    pointer-events: none;
    color: $gray-l3;
  }
}

.overlay {
  @extend %ui-depth4;

  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: transparent;
}