<style>
.test {
	width: 200px;
	height: 200px;
        border:10px solid black;
        background-color:lime;
        -webkit-mask-image: url(resources/mask-top-left.png), url(resources/mask-top-right.png), url(resources/mask-bottom-left.png), url(resources/mask-bottom-right.png),
                            url(resources/mask-top.png), url(resources/mask-right.png), url(resources/mask-bottom.png), url(resources/mask-left.png), url(resources/mask-center.png);
        -webkit-mask-position: top left, top right, bottom left, bottom right, top center, center right, bottom center, center left, center;
        -webkit-mask-origin: border;
        -webkit-mask-repeat: no-repeat, no-repeat, no-repeat, no-repeat, repeat-x, repeat-y, repeat-x, repeat-y, repeat;
        -webkit-mask-composite: copy;
}

</style>

The lime div below should have a soft glow effect.

<div class="test"></div>