html::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: #c0c;
  z-index: 9999;
  opacity: 0;
  transition: width 0.4s ease-out, opacity 0.2s;
  pointer-events: none;
}

/* State Loading: Slowly progressing to 90% */
html[data-briz-loading="true"]::before {
  opacity: 1;
  width: 90%; 
  /* We give you 10 seconds so you don't get stuck if the connection is slow. */
  transition: width 10s cubic-bezier(0.1, 0.05, 0.1, 1);
}

/* State Completed: Jump to 100% */
html[data-briz-loading="done"]::before {
  opacity: 1;
  width: 100%;
  transition: width 0.2s ease-out;
}