framework/less/lib/Dropdown.less

.Dropdown {
  position: relative;
}
.Dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  z-index: @zindex-dropdown;
  display: none;
  min-width: 160px;
  padding: 8px 0;
  margin: 7px 0 0;
  background: @body-bg;
  border-radius: @border-radius;
  .box-shadow(0 2px 6px @shadow-color);
  list-style: none;
  text-align: left;
  color: @text-color;
  font-size: 13px;
  line-height: 1.5;

  .open & {
    display: block;
  }

  > li {
    > a, > button {
      padding: 8px 15px;
      display: block;
      width: 100%;
      color: @text-color;
      border-radius: 0;
      border: 0;
      background: none;
      white-space: nowrap;
      .box-shadow(none);
      text-align: left;
      font-size: 13px;
      font-weight: normal;
      text-decoration: none;

      &.hasIcon {
        padding-left: 40px;
      }
      &:hover, &:focus {
        background: @control-bg;
        outline: none;
      }

      .Button-icon {
        float: left;
        margin-left: -25px;
        margin-top: 2px;
      }
    }
    &.active {
      > a, > button {
        background: @control-bg;
      }
    }
  }
}
.Dropdown-menu--right {
  left: auto;
  right: 0;
}
.Dropdown-header {
  padding: 10px 15px;
  color: @heading-color;
  text-transform: uppercase;
  font-size: 12px;
  font-weight: bold;
  margin-top: 8px;
  border-top: 1px solid @control-bg;
  white-space: nowrap;

  &:first-child {
    margin-top: -8px;
    border-top: 0;
  }
}
.Dropdown-separator {
  margin: 8px 0;
  background-color: @control-bg;
  height: 1px;
}


.dropdown-backdrop {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  top: 0;
  z-index: (@zindex-dropdown - 10);
}


@media @tablet-up {
  .Dropdown--split {
    .Dropdown-toggle .Button-icon {
      display: none;
    }
    .Dropdown-toggle .Button-caret {
      display: inline;
    }

    &.itemCount1 {
      .Button {
        border-radius: @border-radius !important;
      }
      .Dropdown-toggle {
        display: none;
      }
    }

    .Dropdown-menu li:first-child {
      &, + li.Dropdown-separator {
        display: none;
      }
    }
  }
}

.Dropdown--expanded() {
  .Dropdown-toggle {
    display: none;
  }
  .Dropdown-menu {
    display: block;
    border: 0;
    width: auto;
    margin: 0;
    padding: 0;
    min-width: 0;
    float: none;
    position: static;
    background: none;
    .box-shadow(none);
  }
}


@media @phone {
  .Dropdown.open {
    z-index: @zindex-modal;
  }
  .Dropdown-menu {
    margin: 0;
    position: fixed;
    left: 0 !important;
    right: 0 !important;
    width: auto !important;
    bottom: 0;
    top: auto;
    padding: 0;
    padding-bottom: 40px !important;
    display: block;
    max-height: 70vh;
    border-radius: 0;
    .box-shadow(0 2px 6px @shadow-color);
    visibility: hidden;
    overflow: auto;
    -webkit-overflow-scrolling: touch;
    .translate3d(0, 70vh, 0);
    .transition-transform(~" 0.3s, visibility 0s 0.3s");

    > li {
      > a, > button {
        background: @body-bg;
        font-size: 16px;
        padding: 15px 20px;

        &.hasIcon {
          padding-left: 50px;
        }
        .Button-icon {
          font-size: 16px;
          margin-left: -30px;
        }
        &:hover {
          background: @control-bg;
        }
      }
    }
    > .active {
      > a, > button {
        &, &:hover {
          background: @primary-color !important;
          color: #fff !important;
        }
      }
    }
    .open & {
      -webkit-transform: none;
              transform: none;
      visibility: visible;
      transition-delay: 0s;
    }
  }
  .Dropdown-separator {
    margin: 0;
  }
  .dropdown-backdrop {
    background: fade(@secondary-color, 90%);
    opacity: 0;
    .transition(~"opacity 0.3s");
    .translate3d(0, 0, 0);

    .open & {
      opacity: 1;
    }
  }
}