@mixin pretty-buttons($color, $background, $text-shadow: none) {
    color: $color;
    @include gradient-vertical(lighten($background, 5%), darken($background, 5%), 0%, 100%);
    border-color: darken($background, 10%);
    border-bottom-color: darken($background, 20%);
    text-shadow: $text-shadow;
    @include box-shadow(inset 0 1px 0 rgba(255, 255, 255, .1));

    &:hover,
    &:focus,
    &:active,
    &.active {
        @include gradient-vertical(darken($background, 0), darken($background, 10%), 0%, 100%);
        border-color: darken($background, 20%);
        color: $color;
    }

    &.disabled,
    &[disabled],
    fieldset[disabled] & {
        &,
        &:hover,
        &:focus,
        &:active,
        &.active {
            background-color: $background;
            border-color: darken($background, 5%);
        }
    }
}

.btn {
  &.btn-default {
    @include pretty-buttons($btn-default-color, $btn-default-bg);
  }
  &.btn-primary {
    @include pretty-buttons($btn-primary-color, $btn-primary-bg);
  }
  &.btn-success {
    @include pretty-buttons($btn-success-color, $btn-success-bg);
  }
  &.btn-info {
    @include pretty-buttons($btn-info-color, $btn-info-bg);
  }
  &.btn-warning {
    @include pretty-buttons($btn-warning-color, $btn-warning-bg);
  }
  &.btn-danger {
    @include pretty-buttons($btn-danger-color, $btn-danger-bg);
  }
  &.btn-inverse {
    @include pretty-buttons(white, #474949);
  }
}

.btn-outline {
    background-color: transparent;
    background-image: none !important;
    color: inherit;
    transition: all .5s;
}

.btn-default.btn-outline {
    color: #999;
}

.btn-primary.btn-outline {
    color: #428bca;
}

.btn-success.btn-outline {
    color: #5cb85c;
}

.btn-info.btn-outline {
    color: #5bc0de;
}

.btn-warning.btn-outline {
    color: #f0ad4e;
}

.btn-danger.btn-outline {
    color: #d9534f;
}

.btn-primary.btn-outline:hover,
.btn-success.btn-outline:hover,
.btn-info.btn-outline:hover,
.btn-warning.btn-outline:hover,
.btn-danger.btn-outline:hover {
    color: #fff;
}