/**
 * adds a css outline to an element with compatibility for IE8/outline-offset
 * NOTE: the element receiving the outline must be positioned (either relative or absolute)
 * in order for the outline to work in IE8
 *
 * @param {number} [$width=1px]
 * The width of the outline
 *
 * @param {string} [$style=solid]
 * The style of the outline
 *
 * @param {color} [$color=#000]
 * The color of the outline
 *
 * @param {number} [$offset=0]
 * The offset of the outline
 *
 * @param {number/list} [$border-width=0]
 * The border-width of the element receiving the outline.
 * Required in order for outline-offset to work in IE8
 *
 * @param {boolean} [$pseudo=false]
 * `true to always use a pseudo element to render the outline.
 * by default this behavior is limited to IE8 only, but can be enabled in all browser
 * when required
 * 
 * @member Global_CSS
 * @private
 */
@mixin css-outline(
    $width: 1px,
    $style: solid,
    $color: #000,
    $offset: 0,
    $border-width: 0,
    $pseudo: false
) {
    @mixin css-outline-pseudo() {
        &:after {
            position: absolute;
            content: ' ';
            top: -$offset - $width - top($border-width);
            right: -$offset - $width - right($border-width);
            bottom: -$offset - $width - bottom($border-width);
            left: -$offset - $width - left($border-width);
            border: $width $style $color;
            pointer-events: none;
        }
    }
    @if $pseudo {
        @include css-outline-pseudo;
    } @else {
        outline: $width $style $color;
        outline-offset: $offset;

        @if $include-ie and ($offset == 0) {
            .#{$prefix}ie8 & {
                outline: none;
                @include css-outline-pseudo;
            }
        }
        @if $offset != 0 {
            .#{$prefix}ie &,
            .#{$prefix}ie10p &,
            .#{$prefix}edge & {
                outline: none;
                @include css-outline-pseudo;
            }
        }
    }
}