Image inner glow effect for https://github.com/FormidableLabs/nuka-carousel

carousel.scss

//// ../../styles/_mixins.scss
// @mixin prefix($property, $value, $prefixes: webkit moz ms o) {
//     @each $prefix in $prefixes {
//         -#{$prefix}-#{$property}: $value;
//     }
//     #{$property}: $value;
// }

// @mixin same-value($value, $properties) {
//     @each $property in $properties {
//         #{$property}: $value;
//     }
// }

@import "../../styles/mixins";

.slider-slide {
    cursor: default;
    img {
        @include prefix(filter, grayscale(70%));
    }
    &:after {
        $same-size: 100%;
        content: '';
        position: absolute;
        @include same-value($same-size, width height);
        @include same-value(0, top left);
        @include prefix(background, radial-gradient(circle, rgba(255,255,255,1) 0%, rgba(154,154,154,1) 35%, rgba(0,0,0,1) 100%));
        @include prefix(mix-blend-mode, multiply);
    }
}