html, body{height:100%; margin:0;padding:0}

body {
    padding-top: 0px;
    padding-bottom: 0px;
    background-color:  darkgrey;
}


.panel > .panel-body + .panel-body {
 border-top: 1px solid #dddddd;
}
.div-bordered {
  border: 1px solid #dddddd;
}
 #overlay {
    background-color: #ccc; /*or semitransparent image*/
    opacity: 0.5;
    display: none;
    height: 100%;
    width: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 100;
}