Style file-inputs in webkit browsers only.

gistfile1.scss

// Style file-upload for webkit-based browsers
@media screen and (-webkit-min-device-pixel-ratio:0) {
  input[type="file"] {
    background: #fff;
    border: 1px solid $tan;
    @include border-radius(0 2px 2px 0);
    @include box-sizing(border-box);
    color: #666;
    font-size: 14px;
    height: 32px;
    @include linear-gradient(#ffffe8, white);
    margin-left: 77px;
    padding: 4px 15px;
    position: relative;
    text-indent: -200px;
    width: 500px;
    @include transition;

    &::before {
      @include border-radius(2px 0 0 2px);
      border: 1px solid $tan-dark;
      @include box-sizing(border-box);
      color: #FFF;
      content: 'Select File';
      display: block;
      font-size: 14px;
      font-weight: bold;
      height: 32px;
      left: -78px;
      @include linear-gradient(#F3BC00, #E0A002);
      padding: 9px 10px;
      position: absolute;
      text-align: center;
      text-indent: 0;
      text-shadow: #333 1px 1px 1px;
      @include title-font;
      top: -1px;
      @include transition;
      width: 100px;
    }
    &:focus, &:hover {
      border: 1px solid $tan-dark;
    }
  }
}