@mixin radius ($radius) {
    @if $supports-border-radius == true {
        -webkit-border-radius: $radius;
        -moz-border-radius: $radius;
        border-radius: $radius;
        behavior:url(css/PIE.htc);
    }
}

@mixin gradient ($color1, $color2) {
    background-image: -moz-linear-gradient(top, $color1, $color2);
    background-image: -ms-linear-gradient(top, $color1, $color2);
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from($color1), to($color2));
    background-image: -webkit-linear-gradient(top, $color1, $color2);
    background-image: -o-linear-gradient(top, $color1, $color2);
    background-image: linear-gradient(top, $color1, $color2);
    background-repeat: repeat-x;
    -pie-background: linear-gradient($color1, $color2);
}


@function linear-gradient-bevel($direction, $bg-color) {
    @return linear-gradient($direction, color_stops(
        lighten($bg-color, 15%),
        lighten($bg-color, 8%) 30%,
        $bg-color 65%,
        darken($bg-color, 6%)
    ));
}

@function linear-gradient-glossy($direction, $bg-color) {
    @return linear-gradient($direction, color_stops(
        lighten($bg-color, 15%),
        lighten($bg-color, 5%) 50%,
        $bg-color 51%,
        darken($bg-color, 5%)
    ));
}

@function linear-gradient-recessed($direction, $bg-color) {
    @return linear-gradient($direction, color_stops(
        darken($bg-color, 10%),
        darken($bg-color, 5%) 10%,
        $bg-color 65%,
        lighten($bg-color, .5%)
    ));
}

@function linear-gradient-matte($direction, $bg-color) {
    @return linear-gradient($direction, color_stops(
        lighten($bg-color, 3%),
        darken($bg-color, 4%)
    ));
}

@function linear-gradient-matte-reverse($direction, $bg-color) {
    @return linear-gradient($direction, color_stops(
        darken($bg-color, 6%),
        lighten($bg-color, 4%)
    ));
}

@function linear-gradient-menu-bevel($direction, $bg-color) {
    @return linear-gradient($direction, color_stops(
        lighten($bg-color, 65%),
        lighten($bg-color, 40%) 30%,
        $bg-color 95%,
        $bg-color
    ));
}


@function linear-gradient-panel-title($direction, $bg-color) {
    @return linear-gradient($direction, color_stops(
        lighten($bg-color, 28%),
        lighten($bg-color, 2%) 44%,
        $bg-color 47%,
        $bg-color
    ));
}

@function linear-gradient-btn-glossy($direction, $bg-color) {
    @return linear-gradient($direction, color_stops(
        lighten($bg-color, 50%) 0%,
        lighten($bg-color, 45%) 13%,
        lighten($bg-color, 25%) 53%,
        darken($bg-color, 3%) 60%,
        $bg-color 80%,
        lighten($bg-color, 7%) 100%
    ));
}

@mixin background-gradient($bg-color, $type: $base-gradient, $direction: top) {
    @if $base-gradient != null and $bg-color != transparent {
        $gradient: null;

        //color_stops
        @if type-of($type) == "list" {
            $gradient: linear-gradient($direction, $type);
        }

        //default gradients
        @else if $type == bevel {
            $gradient: linear-gradient-bevel($direction, $bg-color);
        } @else if $type == glossy {
            $gradient: linear-gradient-glossy($direction, $bg-color);
        } @else if $type == recessed {
            $gradient: linear-gradient-recessed($direction, $bg-color);
        } @else if $type == matte {
            $gradient: linear-gradient-matte($direction, $bg-color);
        } @else if $type == matte-reverse {
            $gradient: linear-gradient-matte-reverse($direction, $bg-color);
        } @else if $type == menu-bevel {
            $gradient: linear-gradient-menu-bevel($direction, $bg-color);
        } @else if $type == panel-title {
            $gradient: linear-gradient-panel-title($direction, $bg-color);
        } @else if $type == btn-glossy {
            $gradient: linear-gradient-btn-glossy($direction, $bg-color);
        }

        @if $gradient != null {
            @include background-image($gradient);
//            @include filter-gradient(#f2f1ec, #66f1ec, vertical);
            -pie-background: $gradient;
        }
    }
}