html, body {
  min-height: 100%;
}

.ui-blocker {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 100%;
}

.ui-blocker .ui-blocker-wrapper {
  position: absolute;
  height: 48px;
  width: 48px;
  left: 50%;
  top: 50%;
  margin: -24px 0 0 -24px;
  background-color: #ccc;
  opacity: 0.8;
  border-radius: 4px; 
  padding: 8px;
  box-sizing: border-box;
}

.ui-blocker .ui-blocker-spinner {
  background-image: url(loading.gif);
  height: 32px;
  width: 32px;
  margin: auto;
}