html,
body {height: 100%;}

.carousel,
.item,
.active {height: 100%;}

.carousel-inner {height: 100%; top: 0;}
.fill {width: 100%; background-color: rgba(0,0,0, 0.7); height: 100%; background-position: center;
    background-size: cover; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover;}