z-index issue

dabblet.css

/* z-index issue */
.img {
	background:#fff;
	position:relative;
	width:500px;
	height:344px;
	border:1px solid black;
	padding:10px;
}

.img:after {
	content:'';
	z-index:-1;
	position:absolute;
	bottom:-5px;
	left:10px;
	width:50%;
	height:20%;
	-webkit-box-shadow:0 15px 10px rgba(0, 0, 0, 0.7);
	-moz-box-shadow:0 15px 10px rgba(0, 0, 0, 0.7);
	box-shadow:0 15px 10px rgba(0, 0, 0, 0.7);
}

dabblet.html

<div class="img"><img src="http://lorempixel.com/500/344"></div>

settings.json

{"view":"split-vertical","fontsize":"100","seethrough":"","prefixfree":"1","page":"all"}