_forms.scss

form.awesome {

  // Defaults for custom inputs
  .custom {
    display: inline-block;
    width: 16px;
    height: 16px;
    position: relative;
    top: 2px;
    border: solid 1px $custom-form-border-color;
    background: $custom-form-bg;
  }

  // Custom radio button and checkbox
  input[type="radio"],
  input[type="checkbox"] {
    position: absolute;
    left: -100000px;

    + label {
      &:before {
        @extend .custom;
        content: "";
        margin-right: 0.5em;
      }
    }
  }

  input[type="radio"] {
    + label {
      position: relative;

      &:before {
        @include radius(1000px);
      }
    }

    &:checked {
      + label:after {
        content: "";
        display: block;
        width: 8px;
        height: 8px;
        @include radius(1000px);
        background: $custom-form-check-color;
        position: absolute;
        top: 6px;
        #{$default-float}: 4px;
      }
    }
  }

  input[type="checkbox"] {
    + label:before {
      content: "\00d7";
      display: inline-block;
      line-height: 0.8;
      text-align: center;
      top: 0;
      #{$default-float}: 0;
      font-size: 16px;
      font-weight: normal;
      color: $custom-form-bg;
    }

    &:checked {
      + label:before {
        color: $custom-form-check-color;
      }
    }
  }

  // Custom select box
  .dropdown {
    display: block;
    position: relative;
    top: 0;
    height: $custom-select-height;
    margin-bottom: $custom-select-margin-bottom;
    margin-top: 0px;
    padding: 0px;
    width: 100%;
    background: $custom-dropdown-bg;
    background: -moz-linear-gradient(top, $custom-dropdown-bg 0%, $custom-select-fade-to-color 100%);
    background: -webkit-linear-gradient(top, $custom-dropdown-bg 0%,$custom-select-fade-to-color 100%);
    background: linear-gradient(to bottom, $custom-dropdown-bg 0%,$custom-select-fade-to-color 100%);
    -webkit-box-shadow: none;
    box-shadow: none;
    font-size: emCalc(14px);
    vertical-align: top;

    .selector {
      cursor:default;
      position: absolute;
      width: $form-spacing * 1.5;
      height: $custom-select-height - emCalc(2px);
      display: block;
      #{$opposite-direction}: 0;
      top: 0;

      // Add background to selector to hide the ugly little non-WebKit dropdown arrow
      background: $custom-dropdown-bg;
      background: -moz-linear-gradient(top, $custom-dropdown-bg 0%, $custom-select-fade-to-color 100%);
      background: -webkit-linear-gradient(top, $custom-dropdown-bg 0%,$custom-select-fade-to-color 100%);
      background: linear-gradient(to bottom, $custom-dropdown-bg 0%,$custom-select-fade-to-color 100%);

      // Remove the background in WebKit since WebKit doesn't render the ugly arrow
      @media screen and (-webkit-min-device-pixel-ratio:0) {
        background: none;
      }

      // Pass clicks through the selector to the select element in WebKit and Mozilla
      pointer-events: none;

      &:after {
        content: "";
        display: block;
        @include css-triangle(5px, $custom-select-triangle-color, top);
        position: absolute;
        left: 0;
        top: 50%;
        margin-top: -3px;
      }
    }
  
    &:hover,
    :focus + {
      .selector {
        &:after { @include css-triangle(5px, $custom-select-triangle-color-open, top); }
      }
    }

    :disabled {
      color: $custom-select-disabled-color;
      &:hover {
        background: transparent;
        color: $custom-select-disabled-color;
        &:after { display: none; }
      }
    }

    select {
      // Make sure we're doing sizing in a sane manner
      @include box-sizing(border-box);

      // Set appearance to none in order to style the select
      -webkit-appearance: none;
      -moz-appearance: none;
      appearance: none;

      // Reset the form element
      margin: 0;
      padding: 0;
      font-size: 100%;
      line-height: inherit;
      font-family: inherit;
      vertical-align: middle;

      // Get rid of backgrounds and borders
      border: none;
      background: none;

      // Modified version of Foundation's style for the selected item display
      color: $input-font-color;

      line-height: emCalc(24px);
      height: $custom-select-height - emCalc(2px);
      padding: ($custom-select-height - emCalc(24px)) / 2
                $form-spacing / 2;

      padding-right: 0;

      // Make sure text does not leak under the dropdown arrow in WebKit
      @media screen and (-webkit-min-device-pixel-ratio:0) {
        padding-right: 2em;
      }
    }
  }
}

// Make things look sane in IE
.lt-ie9 form.awesome {
  input[type="radio"],
  input[type="checkbox"] {
    position: static;

    + label:before {
      content: none;
    }
  }
}

.lt-ie8 form.awesome {
  .custom.dropdown {
    overflow: hidden;

    .selector {
      display: none;
    }

    select {
      margin: -2px;
      height: $custom-select-height + emCalc(4px);
    }
  }
}

forms.js.coffee

wrapSelects = ->
  $('form.awesome select:not(.is-wrapped)')
    .addClass('is-wrapped')
    .wrap('<div class="custom dropdown select" />')
    .after('<span class="selector"></span>')

$(wrapSelects)

Thanks for documenting this! Really, really helpful.

You're welcome. Thanks for the nice comment!