#page-preloader {
  position: fixed;
  left: 0;
  top: 0;
  right: 0;
  bottom: 0;
  background: #00a5f1;
  z-index: 100500;
}

#page-preloader .spinner {
  width: 100px;
  height: 100px;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  margin: auto;

  border: 16px solid #f3f3f3; /* Light grey */
  border-top: 16px solid rgba(0,0,0, .5); /* Blue */
  border-radius: 50%;
  animation: spin 2s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}