html,
body {
  height: 100%;
}

.box_gray {
  background-color: #25353c;
  min-height: 100%;
}

.white_box {
  background-color: white;
}

.clear {
  clear: both;
}

.overlay {
  width: 100%;
  height: 100%;
  position: fixed;
  top: 0;
  left: 0;
  display: none;
  z-index: 50;
}

.overlay_gray {
  width: 100%;
  height: 100%;
  position: fixed;
  top: 0;
  left: 0;
  display: none;
  z-index: 50;
  background-color: #000;
  opacity: 0.7;
}